Handling a few more code paths in the meta.mk

Including:
* trying to clean when there is nothing to clean
* allowing tagging only w/o building
* trying to tag when there is nothing to tag
Fixing minor errors in new meta.mk logic
Pulling before pushing so as not to overwrite history
Allowing pulling to fail
Merge pull request #8 from modcloth/handling-more-stuff-in-makefile

Handling a few more code paths in the meta.mk