Run 'git up' from not top-level dir
Rewritten 'stash' and 'returning_to_current_branch'

Now using contextlib.contextmanager
Some refactoring

- Made 'remote_map', 'branches' and 'remotes' variables
- Sorted code and added some comments
Removed obsolete memorize-decorator
Added git wrapper
Added setup.py
Renamed project
Refacored big fat PyGitUp.py to more OOP
Added Exception handling (not tested), more docs
Updated readme