[Version Control] Log Widget fixes:

[Win32] Fixed an issue with relative repository checkouts.
Fixed an issue with items which didn't exist anymore.
Moved RootPath to Repository. It's logical that a repository should have a
checkout location.
[Version Control] Log Widget:

Fixed issues with added/deleted files in log widget.
[Version Control] Log Widget - No longer break API.
[Version Control] Log Widget - Win32 peg revision is assigned from SvnTarget.
[Version Control] Log Widget - Trimmed down number of swallowed exceptions.
[Version Control] Fixup exception handling.
[Version Control] Log Widget

Trim down number of swallowed exceptions again.
Don't allow expanding directories.
Merge pull request #338 from mono/fixLogWidget

[Version Control] Log Widget