__unicode__ function must use u'' format strings (see registration app for an example like these changes.
adding tests
making __unicode__ work on unsaved objects; gracefully failing sign() on unsaved objects
unicode tests for main objects
Merge branch 'develop' of github.com:learningequality/ka-lite into __unicode__support

Conflicts:
	kalite/contact/tests/__init__.py
made get_uuid assert good values, rather than full_clean; modularized test code
Merge pull request #313 from bcipolli/__unicode__support

__unicode__ support for unicode characters in some models .. plus a bit more :(