Theme engine support.

Updated 4.2 support for the old T-Mobile theme engine, as usual
needs the provider and switcher apps installed as well.

I'm finally dropping the 400+ commit history on this, since everybody
else keeps picking it up from CM as a single patch anyway... But
for the record, nothing of this would be possible without Josh, Ed,
and the rest of the TMo guys who wrote and maintained it until 2.2:

amit chabra <amit.chabra@t-mobile.com>
Amit Kohli <amit.kohli@t-mobile.com>
Chris Cogar <chriscogar@t-mobile.com>
Dirk Sigurdson <dirk.sigurdson@t-mobile.com>
Ed Carrigan <edward.carrigan@t-mobile.com>
Gaurav Sharma <gaurav.sharma3@t-mobile.com>
Hui Feng <hui.feng@t-mobile.com>
John Ritz <john.ritz1@t-mobile.com>
Josh Guilfoyle <josh.guilfoyle@t-mobile.com>
Mark Roberts <mark.roberts48@t-mobile.com>
Pankaj Kumar <Pankaj.kumar6@t-mobile.com>
Samuel Cheung <samuel.cheung@t-mobile.com>
Sergey Ten <sergey.ten6@t-mobile.com>

Change-Id: I7148d51be48f28a2dc4bdf9ec9018f04b268ffc4