GNU GENERAL PUBLIC LICENSEVersion 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 copiesof this license document, but changing it is not allowed.------------------------------------------------------------------------Preamble  The licenses for most software are designed to take away yourfreedom to share and change it.  By contrast, the GNU General PublicLicense is intended to guarantee your freedom to share and change freesoftware--to make sure the software is free for all its users.  ThisGeneral Public License applies to most of the Free SoftwareFoundation's software and to any other program whose authors commit tousing it.  (Some other Free Software Foundation software is covered bythe GNU Library General Public License instead.)  You can apply it toyour programs, too.  When we speak of free software, we are referring to freedom, notprice.  Our General Public Licenses are designed to make sure that youhave the freedom to distribute copies of free software (and charge forthis service if you wish), that you receive source code or can get itif you want it, that you can change the software or use pieces of itin new free programs; and that you know you can do these things.  To protect your rights, we need to make restrictions that forbidanyone to deny you these rights or to ask you to surrender the rights.These restrictions translate to certain responsibilities for you if youdistribute copies of the software, or if you modify it.  For example, if you distribute copies of such a program, whethergratis or for a fee, you must give the recipients all the rights thatyou have.  You must make sure that they, too, receive or can get thesource code.  And you must show them these terms so they know theirrights.  We protect your rights with two steps: (1) copyright the software, and(2) offer you this license which gives you legal permission to copy,distribute and/or modify the software.  Also, for each author's protection and ours, we want to make certainthat everyone understands that there is no warranty for this freesoftware.  If the software is modified by someone else and passed on, wewant its recipients to know that what they have is not the original, sothat any problems introduced by others will not reflect on the originalauthors' reputations.  Finally, any free program is threatened constantly by softwarepatents.  We wish to avoid the danger that redistributors of a freeprogram will individually obtain patent licenses, in effect making theprogram proprietary.  To prevent this, we have made it clear that anypatent must be licensed for everyone's free use or not licensed at all.  The precise terms and conditions for copying, distribution andmodification follow.---------------------------------------------------------------------TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION0.This License applies to any program or other work which contains anotice placed by the copyright holder saying it may be distributedunder the terms of this General Public License.  The "Program", below,refers to any such program or work, and a "work based on the Program"means either the Program or any derivative work under copyright law:that is to say, a work containing the Program or a portion of it,either verbatim or with modifications and/or translated into anotherlanguage.  (Hereinafter, translation is included without limitation inthe term "modification".)  Each licensee is addressed as "you".Activities other than copying, distribution and modification are notcovered by this License; they are outside its scope.  The act ofrunning the Program is not restricted, and the output from the Programis covered only if its contents constitute a work based on theProgram (independent of having been made by running the Program).Whether that is true depends on what the Program does.1.You may copy and distribute verbatim copies of the Program's sourcecode as you receive it, in any medium, provided that you conspicuouslyand appropriately publish on each copy an appropriate copyright noticeand disclaimer of warranty; keep intact all the notices that refer tothis License and to the absence of any warranty; and give any otherrecipients of the Program a copy of this License along with theProgram.You may charge a fee for the physical act of transferring a copy, andyou may at your option offer warranty protection in exchange for a fee.2.You may modify your copy or copies of the Program or any portion ofit, thus forming a work based on the Program, and copy and distributesuch modifications or work under the terms of Section 1 above,provided that you also meet all of these 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.  Ifidentifiable sections of that work are not derived from the Program,and can be reasonably considered independent and separate works inthemselves, then this License, and its terms, do not apply to thosesections when you distribute them as separate works.  But when youdistribute the same sections as part of a whole which is a work basedon the Program, the distribution of the whole must be on the terms ofthis License, whose permissions for other licensees extend to theentire whole, and thus to each and every part regardless of who wroteit.Thus, it is not the intent of this section to claim rights or contestyour rights to work written entirely by you; rather, the intent is toexercise the right to control the distribution of derivative orcollective works based on the Program.In addition, mere aggregation of another work not based on the Programwith the Program (or with a work based on the Program) on a volume ofa storage or distribution medium does not bring the other work underthe scope of this License.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 ofSections 1 and 2 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 formaking modifications to it.  For an executable work, complete sourcecode means all the source code for all modules it contains, plus anyassociated interface definition files, plus the scripts used tocontrol compilation and installation of the executable.  However, as aspecial exception, the source code distributed need not includeanything that is normally distributed (in either source or binaryform) with the major components (compiler, kernel, and so on) of theoperating system on which the executable runs, unless that componentitself accompanies the executable.If distribution of executable or object code is made by offeringaccess to copy from a designated place, then offering equivalentaccess to copy the source code from the same place counts asdistribution of the source code, even though third parties are notcompelled to copy the source along with the object code.4.You may not copy, modify, sublicense, or distribute the Program exceptas expressly provided under this License.  Any attempt otherwise tocopy, modify, sublicense or distribute the Program is void, and willautomatically terminate your rights under this License.  However,parties who have received copies, or rights, from you under thisLicense will not have their licenses terminated so long as suchparties remain in full compliance.