Log Message:
Update to 8.2.3.  Notable changes:

- TkCVS now supports Subversion (up to 1.7). If SVN repository has a structure
  similar to trunk, branches, and tags but with different names, you can tell
  TkCVS about it.
- The previously undocumented RCS support is explicit now.

- Rework the merge functionality.  There's only one dialog for tagging, which
  you OK when you're ready to commit the merges.
- Merge arrows are drawn in the Branch Browser for merges tracked by
  Subversion 1.5's mergeinfo property and CVSNT's mergepoint feature.

- The Branch Browser positions the diagram so "you are here" is in the \ 
visible
  canvas, fixing a long-time nagging irritation.
- Locking and unlocking for SVN, and some additional SVN-specific right-click
  popups.