Major refactoring.

* Many utility functions moved to tina_util.py.
* Fixed circular import bug.
* A Tinafile is generated between the dry-run and the commit to help
  TINA remember which repos should be tagged, and which pinned.
* A tag type was added to make version bumping and sorting easier.
Squash
Merge remote-tracking branch 'origin/cleanup-and-fix' into berkshelf

Conflicts:
	tina/cookbook_metadata.py
	tina/cookbook_repo.py
	tina/tag.py
	tina/tina.py
	tina/tina_util.py
Combined with refactoring.

Added support for Berkself and metadata.rb dependency resolution.