Time to Remove CVS support

Drupal's moved to Git so not sure why Hacked is still needing to reference CVS.

Possibly hacked_cvs_executable_get_version() needs to get replaced with hacked_git_executable_get_version(), but not sure.

Mostly I don't think it makes any sense to have "Could not find the 'cvs' executable. Checking CVS projects will not work correctly." listed in the status report page on D7 when I don't think that should matter. I can't see how it would matter for D6 sites either, but maybe I don't understand Hacked! well enough.