Revert "Refactor tests to use the PLONE_APP_CONTENTTYPES_FIXTURE instead of the PLONE_FIXTURE. This fixes all test p.a.discussion test failures."

This reverts commit 9049368cbaa4cd2be0df81c5cb5cceef75228fd1.

Conflicts:
	setup.py
Update CHANGES and prepare 2.2.10 release.