roomservice: When validating the presence of a repo, check main manifest too

Change-Id: If680536484074b473458723d93e783d074d7f669
Sign final packages with a different key if requested

...and throw it into recovery builds as well

Change-Id: Ic96d4d49d821cb03d5318e3e9ad93d02fb92573e
Merge remote-tracking branch 'CyanogenMod/cm-10.1' into cm-10.1