Fix DateUtils.formatElapsedTime.

More reuse of StringBuilders, less broken home-grown formatting code.

Long-term, we should hand this over to icu4c, but they're not ready yet.

Bug: http://code.google.com/p/android/issues/detail?id=41401
Bug: 7736688
Change-Id: Ib3c1e1aad05827df646aa18645cce19dffb7551f
Merge "Fix DateUtils.formatElapsedTime." into cm-10.1
Fix ClockStock imports

Change-Id: Id4da991775984ab6c652f54847d409cbb71316b2
merge changes from remotes/github/cm-10.1 into master