Issues with rollback command

[SimonEast]

There's currently two issues with the --rollback command.

1. It doesn't handle submodules correctly. See source code note here.
2. It returns the working copy to the master branch, which may not be what the user intended. See source code note here.

I'm unlikely to have time to fix these any time soon unfortunately, but if anyone else wants to have a go, feel free. 👍

[banago]

@SimonEast this issue of returning to master after rollback is now fixed by this super-awesome contrbutor @GuidoHendriks.

For the submodule handle, I don't see how it can be implemented - I'm out of ideas. What's on your mind?

[banago]

Submodule rollback won't work at this time.