Upgrade cvs2svn to version 2.1.1.

Changes from 2.1.0 to 2.1.1:
- Adjust test suite for upstream changes in the svntest code.

Changes from 2.0.1 to 2.1.0:
- Allow conversion of a CVS repository to git.
- Support mapping from cvs author names to git "Author <email>" form.
- Add SymbolMapper, for transforming specific symbols in specific files.
- Allow SymbolTransforms to cause a symbol to be discarded.
- Write each CVS branch/tag to be written to an arbitrary SVN path.
- Choose which trunk/branch should serve as the parent of each branch/tag.
- --symbol-hints: manually specify how symbols should be converted.
- Make symbol strategy rules project-specific.
- --write-symbol-info: output info about CVS symbols.
- Add option ctx.decode_apple_single for handling AppleSingle-encoded files.
- Add a new, restartable pass that converts author and log_msg to unicode.
- Allow properties to be left unset via auto-props using a leading '!'.
- Polish to work well under Python 2.5.
- Create trunk/tags/branches directories for project when project is created.
- Improved conversion speed significantly, especially for large repositories.
- Ignore (with a warning) symbols defined to malformed revision numbers.
- Tolerate multiple definitions of a symbol to the same revision number.
- Handle RCS files that superfluously set the default branch to trunk.
- Allow '/' characters in CVS symbol names (creating multilevel SVN paths).
- Allow symbols to be transformed to contain '/' (allowing multilevel paths).
- Convert '\' characters to '/' (rather than '--') in symbol names.
- Make encoding problems fatal; to resolve, restart at CleanMetadataPass.
- Change the default symbol handling option to --symbol-default=heuristic.

(tonnerre)