Fix Vs2012 naming

It was inconsistent with previous VS version naming.
Remove VS2012 Debug Configuration
Add VS2013 support
Fix incorrect registry path and method name
Manage case where a branch can't be initialized to avoid infinit loop

For the moment, there is the case of a renamed branch not managed because we can't find the root changeset in the repository
Merge pull request #463 from pmiossec/managed_branch_not_initializable

Manage case where a branch can't be initialized to avoid infinit loop
Enable VS2013 client build in Debug|x86.
Alias GitTfs.vs2012 and GitTfs.Vs11 (when referenced from GIT_TFS_CLIENT).
Extract a base class for VS2012 and VS2013.
The VS2012 and VS2013 Workspace.Checkin methods are the same, so use the same code.
Merge pull request #464 from DanRigby/VS2013

Add support for VS2013 & TFS2013