am 5306e0a8: Merge "SIP: add PEER_NOT_REACHABLE error feedback." into gingerbread

Merge commit '5306e0a85dabd4c18a7b3f81acc0f582f9429482' into gingerbread-plus-aosp

* commit '5306e0a85dabd4c18a7b3f81acc0f582f9429482':
  SIP: add PEER_NOT_REACHABLE error feedback.