Add more logging.

1) Call state logging was lost in a merge conflict, adding that back.
2) Adding better ringing state logging.  Fixes problems:
  - No more superfluous "STOP_RINGER" logging
  - Adding call-waiting logging
  - More accurate call attribution for start and stop ringing

Change-Id: Ie41340ab6790a6c5f87f5592836b29bf6799708d