merge version `utorrent-ppc.rb` into `utorrent.rb`

and update license.

Intention: to delete `utorrent-ppc.rb` from versions.

I was surprised to find any PPC-requiring Casks at all.  However, this is a good example of why merging is better, as the PPC Cask had acquired a `zap` stanza which was missing in the main Cask.

@vitorgalvao since Rosetta was discontinued in Lion, the to-be-deleted versions Cask in practice required <= Snow Leopard.