Support for other version control

[hayd]

Please add requests for other VC support here:

• git
• hg
• bzr (this wasn't very cleanly implemented!, see PR ENH add bazaar #53).
• svn
  ...

I had hoped that PR #37 would act as a "guide" to adding additional VCS support...

[hayd]

Some ideas here: https://github.com/mgedmin/check-manifest/blob/master/check_manifest.py (also they use some clever HG stuff for files changed, which may be better than ours).

[hayd]

Note: you can pass in a diff, so this isn't too important:

svn diff | pep8radius --from-diff=-