The GNU General Public License (GPL)Version 2, June 1991Copyright (C) 1989, 1991 Free Software Foundation, Inc.59 Temple Place, Suite 330, Boston, MA 02111-1307 USAEveryone is permitted to copy and distribute verbatim copies of this licensedocument, but changing it is not allowed.PreambleThe licenses for most software are designed to take away your freedom to shareand change it.  By contrast, the GNU General Public License is intended toguarantee your freedom to share and change free software--to make sure thesoftware is free for all its users.  This General Public License applies tomost of the Free Software Foundation's software and to any other program whoseauthors commit to using it.  (Some other Free Software Foundation software iscovered by the GNU Library General Public License instead.) You can apply it toyour programs, too.When we speak of free software, we are referring to freedom, not price.  OurGeneral Public Licenses are designed to make sure that you have the freedom todistribute copies of free software (and charge for this service if you wish),that you receive source code or can get it if you want it, that you can changethe software or use pieces of it in new free programs; and that you know youcan do these things.To protect your rights, we need to make restrictions that forbid anyone to denyyou these rights or to ask you to surrender the rights.  These restrictionstranslate to certain responsibilities for you if you distribute copies of thesoftware, or if you modify it.For example, if you distribute copies of such a program, whether gratis or fora fee, you must give the recipients all the rights that you have.  You mustmake sure that they, too, receive or can get the source code.  And you mustshow them these terms so they know their rights.We protect your rights with two steps: (1) copyright the software, and (2)offer you this license which gives you legal permission to copy, distributeand/or modify the software.Also, for each author's protection and ours, we want to make certain thateveryone understands that there is no warranty for this free software.  If thesoftware is modified by someone else and passed on, we want its recipients toknow that what they have is not the original, so that any problems introducedby others will not reflect on the original authors' reputations.Finally, any free program is threatened constantly by software patents.  Wewish to avoid the danger that redistributors of a free program willindividually obtain patent licenses, in effect making the program proprietary.To prevent this, we have made it clear that any patent must be licensed foreveryone's free use or not licensed at all.The precise terms and conditions for copying, distribution and modificationfollow.TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION0. This License applies to any program or other work which contains a noticeplaced by the copyright holder saying it may be distributed under the terms ofthis General Public License.  The "Program", below, refers to any such programor work, and a "work based on the Program" means either the Program or anyderivative work under copyright law: that is to say, a work containing theProgram or a portion of it, either verbatim or with modifications and/ortranslated into another language.  (Hereinafter, translation is includedwithout limitation in the term "modification".) Each licensee is addressed as"you".Activities other than copying, distribution and modification are not covered bythis License; they are outside its scope.  The act of running the Program isnot restricted, and the output from the Program is covered only if its contentsconstitute a work based on the Program (independent of having been made byrunning the Program).  Whether that is true depends on what the Program does.1. You may copy and distribute verbatim copies of the Program's source code asyou receive it, in any medium, provided that you conspicuously andappropriately publish on each copy an appropriate copyright notice anddisclaimer of warranty; keep intact all the notices that refer to this Licenseand to the absence of any warranty; and give any other recipients of theProgram a copy of this License along with the Program.You may charge a fee for the physical act of transferring a copy, and you mayat your option offer warranty protection in exchange for a fee.2. You may modify your copy or copies of the Program or any portion of it, thusforming a work based on the Program, and copy and distribute such modificationsor work under the terms of Section 1 above, provided that you also meet all ofthese conditions:    a) You must cause the modified files to carry prominent notices stating    that you changed the files and the date of any change.    b) You must cause any work that you distribute or publish, that in whole or    in part contains or is derived from the Program or any part thereof, to be    licensed as a whole at no charge to all third parties under the terms of    this License.    c) If the modified program normally reads commands interactively when run,    you must cause it, when started running for such interactive use in the    most ordinary way, to print or display an announcement including an    appropriate copyright notice and a notice that there is no warranty (or    else, saying that you provide a warranty) and that users may redistribute    the program under these conditions, and telling the user how to view a copy    of this License.  (Exception: if the Program itself is interactive but does    not normally print such an announcement, your work based on the Program is    not required to print an announcement.)These requirements apply to the modified work as a whole.  If identifiablesections of that work are not derived from the Program, and can be reasonablyconsidered independent and separate works in themselves, then this License, andits terms, do not apply to those sections when you distribute them as separateworks.  But when you distribute the same sections as part of a whole which is awork based on the Program, the distribution of the whole must be on the termsof this License, whose permissions for other licensees extend to the entirewhole, and thus to each and every part regardless of who wrote it.Thus, it is not the intent of this section to claim rights or contest yourrights to work written entirely by you; rather, the intent is to exercise theright to control the distribution of derivative or collective works based onthe Program.In addition, mere aggregation of another work not based on the Program with theProgram (or with a work based on the Program) on a volume of a storage ordistribution medium does not bring the other work under the scope of thisLicense.3. You may copy and distribute the Program (or a work based on it, underSection 2) in object code or executable form under the terms of Sections 1 and2 above provided that you also do one of the following:    a) Accompany it with the complete corresponding machine-readable source    code, which must be distributed under the terms of Sections 1 and 2 above    on a medium customarily used for software interchange; or,    b) Accompany it with a written offer, valid for at least three years, to    give any third party, for a charge no more than your cost of physically    performing source distribution, a complete machine-readable copy of the    corresponding source code, to be distributed under the terms of Sections 1    and 2 above on a medium customarily used for software interchange; or,    c) Accompany it with the information you received as to the offer to    distribute corresponding source code.  (This alternative is allowed only    for noncommercial distribution and only if you received the program in    object code or executable form with such an offer, in accord with    Subsection b above.)The source code for a work means the preferred form of the work for makingmodifications to it.  For an executable work, complete source code means allthe source code for all modules it contains, plus any associated interfacedefinition files, plus the scripts used to control compilation and installationof the executable.  However, as a special exception, the source codedistributed need not include anything that is normally distributed (in eithersource or binary form) with the major components (compiler, kernel, and so on)of the operating system on which the executable runs, unless that componentitself accompanies the executable.If distribution of executable or object code is made by offering access to copyfrom a designated place, then offering equivalent access to copy the sourcecode from the same place counts as distribution of the source code, even thoughthird parties are not compelled to copy the source along with the object code.4. You may not copy, modify, sublicense, or distribute the Program except asexpressly provided under this License.  Any attempt otherwise to copy, modify,sublicense or distribute the Program is void, and will automatically terminateyour rights under this License.  However, parties who have received copies, orrights, from you under this License will not have their licenses terminated solong as such parties remain in full compliance.5. You are not required to accept this License, since you have not signed it.However, nothing else grants you permission to modify or distribute the Programor its derivative works.  These actions are prohibited by law if you do notaccept this License.  Therefore, by modifying or distributing the Program (orany work based on the Program), you indicate your acceptance of this License to