[[This is a light weight implementation specification for the"svn:needs-lock" feature on the locking branch.  Its purpose isprimarily to help me iterate through the development of the feature,and secondarily to allow any reviewers to get better idea of my gameplan.  -Fitz ]]svn:needs-lock behaviors:=========================Checkout:- If svn:needs-lock is set on a file when the file is checked out, set  the file to read-only.Update:- If svn:needs-lock is unset in wc, but update sets it:   - If the file has local mods, print a warning and do nothing???  - Else, set file to read-only.- If svn:needs-lock is set in wc, but update unsets it: Set file to  read-write.- If svn:needs-lock is set or unset in both places: Do nothing.- If svn:needs-lock is set and the lock is removed by update (i.e.,  the lock in the wc was defunct):  - If the file has local mods, print a warning and do nothing???  - Else, set the file to read-only. Propset:- Setting the svn:needs-lock property does nothing WRT a file's  permissions.  The file will be set to read-only at commit time.  See  "Commit" below.  (Propset does, however, canonicalizes the value to '*')  Propdel:- Removing svn:needs-lock sets the file to read-write.Propedit:- If the property is changed via propedit, we need to canonicalize it  to '*'.Lock:- If svn:needs-lock is set, the file is set to read-write.Unlock:- If svn:needs-lock is set, the file is set to read-only.Copy:- repos-to-wc or wc-to-wc copy: Ensure that the copy is read-write   even if svn:needs-lock is set as this is another schedule add case.Commit: - If a file has the svn:needs-lock property set and is not locked:  - Unconditionally set the file to read-only.- Else, do nothing.Caveats:- 'svn update' doesn't currently work on Windows if the working files  are read-only, you will need to add some permission changing code.