PEP8 with default constraints.
Add missing PHONY targets, use pep8 for make pep8, new dev address for doc preview.
Update requirement versions.
Remove query_property as parameter of make/extend_declarative_base.
Use unittest2 for better compatibility with Python 2.6.
Add test for query paginate with per_page=0.
Update changes.
Revert back to direct polyfills for missing unittest methods for Python 2.6.