Display git revision information in console window title instead of SVN ...

...Revision.

This method uses "git describe".  The format of the output is as such...

example: 2.0.4-UNSTABLE-4-g0f063d7

This means current compiled revision is ahead of git tag "2.0.4-UNSTABLE" by 4 commits.  Latest commit SHA1 is"g0f063d7".