Consider doing git init by default

[grtjn]

Suggested by Paxton: We want to encourage people to use source control. This makes it easier to start using it. The Roxy new command has a --git flag that does a git init, or we can do that from within slush directly perhaps. Maybe add a small section in the readme or wiki to add a remote to github or unfuddle..

[hunterwilliams]

modified line 148 and added 149 in slushfile.js

    '--branch=' + branch,
    '--git'

and it didn't do a git init on windows as far as I can tell.

[grtjn]

May need a better look. Pushing away for the moment..

[grtjn]

Any votes on this? If we were to do a git init via Roxy or otherwise automatically, we need to document how to connect it with github or other repo..