Brand new Yt version. Supports annotations

Everything changed for good, with separation of models and collections
and more focus on replicating the structure of YouTube API V3.

For this reason, the name changed also from Googol to Yt.
Allow account.playlists.find{|p| ...}

Delegate the iterator to the list
delete_all accepts regex, not just strings

So you can run commands like the following:

account.delete_playlists description: /Playlist .+? Cool/
Don't throttle the *first* subscribe

You only need to wait for 9 seconds *after* a subscription
Merge branch 'yt'