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.
More missing PHONY targets.
Add flatten util methods.
Use relative imports for internal modules.
Overhaul query.search

- Require search config on query property query class instead of on
model.
- Support pagination using subquery join.
- Allow __simple_search__ and __advanced_search__ config to be lists if
__search_filters__ dict used.
Update docs with changes to query search.
Clean up test databases in teardown.
Update location change of QueryProperty.
Remove PEP8 exception mention and change default mkdocs port.
Fix Python2.6 and Python3 compatibility issues.
PEP8/PyLint
Clean up files after make test-full.
Add QueryModel to import.