Checked configuration values for their types. Fixes #1150.
Remove superfluous warning category.
Remove references to outdated warning category.
Changelog for PR#314.
Fix type checking for subclass scenarios.
Spec out configuration type checks.

--HG--
extra : amend_source : 64e8f1a70fb0778646e7575e6614a96d2f7e91d6
Refactor tests.
Merged in lehmannro/sphinx-warnconfig (pull request #314)

Check configuration values for their types