fixed issue with removing CSS Updates category
purging "Wikia CSS Updates" cache once a post is deleted or undeleted
Merge branch 'DAR-304-category-removed-no-cache-purge-fix' into DAR-304
more unit tests
changes after code review: better regex pattern, more descriptive methods' names, more cases for unit tests
hooks - back to the roots
more back-to-the-roots changes
changed regex pattern, fixed unit tests after back-to-the-roots
Merge branch 'DAR-304-code-review-2nd-round' into DAR-304
Merge branch 'dev' into DAR-304
Merge branch 'dev' into DAR-304

Conflicts:
	includes/wikia/tests/WikiaBaseTest.class.php
Merge branch 'DAR-304' into css-chrome

Conflicts:
	extensions/wikia/SpecialCss/SpecialCss.setup.php
	extensions/wikia/SpecialCss/SpecialCssHooks.class.php