Greatly Improve Torrentz Reliability

Currently the Torrentz provider doesn't support shows with scene names (Daily Show), or show that are air-by-date (Also Daily Show).

We fix this by borrowing the KickAss provider's string builders (which grab all possible show names), and simplify _doSearch to support the new strings (which incidentally fixes air-by-date shows).

Cache now also searches for tv shows, since if we don't we get lots of garbage.