Merge https://github.com/fabioz/mu-repo
Implemented unregister action
Added unregister action to the documentation
renamed README.txt to README.rst

This way it is properly rendered in the project's main page.

Also fixed some minor formatting.
Using correct RST formatting in README
Merged unregister.
Merged readme changes.
Removed old README.
Fixing readme.
It's now possible to update and view diff (upd) even if repositories are in different branches.
Merge branch 'master' of https://github.com/fabioz/mu-repo