use flask-sqlalchemy's query_class to override query object
Compatibility with query results without pk field

BaseQuery.paginate() method works now.
Add support for custom analyzer
Merge branch 'master' of https://github.com/miguelgrinberg/Flask-WhooshAlchemy

Conflicts:
	flask_whooshalchemy.py
Merge branch 'master' of https://github.com/zahariash/Flask-WhooshAlchemy

Conflicts:
	flask_whooshalchemy.py
Merge branch 'master' of https://github.com/huxuan/Flask-WhooshAlchemy
Simplify pull from huxuan/Flask-WhooshAlchemy