fixing a possible NullReferenceException
trailing slashes are stripped from incoming TFS repository paths so that exact comparisons match properly.
adding the expected error message to an InitBranchTest to verify that it is throwing the expected exception
fixed the mocked setup of some IBranches to surface an issue with the InitBranch command:

the IBranch structure is a node in a tree containing a path and referencing it's children, thus getting only its children never includes the root path, causing the current implementation of InitBranch to always throw an exception.
fixing a problem with InitBranch where it always failed.
improving the error message when InitBranch fails because it needs a clone of the trunk
When displaying TFS branches, display remotes if there is on matching