Merge branch '2_10'
Merge branch 'master' into async

Conflicts:
	spyne/protocol/xml/model.py
changelog update / version bump
move null test inside ModelBase.validate_native
Merge branch '2_10'
Merge branch 'master' into async
add failing tests to http, refactor flat_dict parsing loop code to separate function
docstring updates and other minor changes.
implement own parse_qs that returns None when the string is not given.
fix frequency tests in http
Merge branch '2_10'
Merge branch 'master' into async
add decimal test
changelog update
changelog update
Merge branch '2_10'
Merge branch 'master' into async
fix misc doc errors
Merge branch '2_10'
Merge branch 'master' into async