Fixed bug when community cookbook lacks name.

If no name is specified in metadata.rb, then it will default to the
repo's local directory.
Addition of interactive frontend.

* Frontend allows a user to mark repos as changed/unchanged, gives
  control over how the version is bumped, and allows the user to select
  how a community cookbook is pinned.
* Repos/community cookbooks are now separated in summary and Tinafile.
* Various other minor refactorings.