Refactored to use nattywad that uses topics support in waddell

Logged here - https://github.com/getlantern/lantern/issues/2055

FYI, as mentioned, I recently reverse merged master into channelwad, so this is (and some other things) have already been reviewed and are already on master.

This is one of the annoyances of having really long lived feature branches, since master can change a fair amount while they're waiting to get merged :)