am 3d7606aa: SIP: enhance timeout and registration status feedback.

Merge commit '3d7606aa607b24817e37c264f2141ed7b2d50be0' into gingerbread-plus-aosp

* commit '3d7606aa607b24817e37c264f2141ed7b2d50be0':
  SIP: enhance timeout and registration status feedback.