Add covers functions
Remove levels from Topic.sync_cover
Add BeautifulSoup as requirements
Fix tests for topics deletion
Add Topic.sync_cover unittests and refactor unittests
Add TransactionTestCase for PollTest
Merge branch 'cover'
Merge branch 'master' into delete_topics

Conflicts:
	pybb/tests/forms/tests.py
Merge branch 'delete_topics' of github.com:thoas/pybbm into delete_topics

Conflicts:
	pybb/tests/forms/tests.py