Improves channel descendants queryset
Updates changelog
Cleans up code
Improves channels long_slug
Improves channel admin
Applies small fix
Merge remote-tracking branch 'opps/stable/0.2.x' into feature-improve-views-queryset

Conflicts:
	CHANGELOG.rst
Merge pull request #395 from mauler/feature-improve-views-queryset

Improve channel querysets in admin and views