Revert "Twitter search channels" to sync with master

This reverts commit f370af0a95ab803486705d32df859fc947140a12.

It never landed in master because it 'leaks' contacts, as in they never
get removed from the channel/blist until the account gets removed, which
becomes a big issue with high activity hashtags.

Sending it back to review, will apply again once it's fixed.