Fix Vs2012 naming

It was inconsistent with previous VS version naming.
Remove VS2012 Debug Configuration
Add VS2013 support
Rewrite FindCommitByCommitMessage to better find by changeset Id

(for better performance and maintainability)
Merge pull request #462 from pmiossec/rewrite_find_by_commit_message

Rewrite FindCommitByCommitMessage to better find by changeset Id
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
Refactoring FindChangesetInGitRepository() not really needed...
Update libgit2sharp from 0.14 to 0.14.1
correction in branch.md doc file...
Merge pull request #465 from pmiossec/update_libgit2sharp

Update libgit2sharp from 0.14 to 0.14.1
Add an option to set a workspace when cloning or init a repository
minor typo
Merge pull request #467 from joshka/patch-1

minor typo in readme - uses cases -> use cases