Rename class from ITunes to Tunes

[dewski]

I would like to rename the wrapper class from ITunes to Tunes. Makes it a little bit more generic so in the future we could potentially add more data sources as well rather than just iTunes.

It's as simple as renaming all instances of ITunes to Tune, and then alias ITunes to Tune.

ITunes = Tunes

Your thoughts @spagalloco?

[stve]

I'm cool with that. The inconsistency between iTunes the product, and ITunes the module never jived with me fully anyway.

[stve]

Going to close this one so we can discuss on #11