Our CVS support worked fine if using :pserver: or similar repository

paths, but had a number of problems if using :ext:, :local:,

:fork:, or others. The path would go through fine, but we'd fail to

strip the leading repository path from any referenced files in diffs,

and fail to strip the trailing ,v. This caused files to show up as

moved, and to not have any syntax highlighting.
On top of this, even if the CVSROOT was one of the blessed ones, a diff

could still end up showing the file as moved, depending on the

RCS File line.
We now have a more complex, thorough CVSROOT parsing function, which

supports validation and cleaning of CVSROOTs, based on the logic found

in CVS itself. This covers all the common (and some uncommon) types of

CVSROOTs, parsing out the correct data for each. It also supports

showing errors to the repository form if some data was invalid (such as

when you try to use passwords or ports for :ext:).
Diff parsing is also smarter now, stripping out the ,v in all cases

and preventing files from showing up as moved.
Unit tests were added for all these conditions.

Unit tests pass.
Tested validation in the repository form by hand.
Tested that :ext: repositories and :local: repositories no longer

result in diffs that appear as plain text and moved.