Moved init-branch VS 2008 specific behavior down to common base class.  In the event of FeatureNotSupported exception, fall back to 2008 behavior.
Merge branch 'master' into issue/306

Conflicts:
	GitTfs.VsCommon/TfsHelper.PostVs2010.Common.cs
Merge pull request #318 from dschilling/issue/306

Fix for init branch issue #306, 2010 client running against 2008 server