Bug 981239 - Use atomic ref-counting for |UnixSocketConsumer|. r=kyle, a=1.3+

|SocketSendTask| acquires a reference to |UnixSocketConsumer| on
the main thread and releases this reference on the I/O thread;
leading to race-conditions. This patch adds

  - atomicity for ref-counting of |UnixSocketConsumer|, and
  - stricter tests in the destructor of this class.
Bug 986752 - CSS :active states get stuck with multiple on-screen touches. r=botond, a=1.4+
Bug 989845 - [bluedroid] Implement KeyPressedCallback to handle HSP commands. r=echou, a=1.4+
Bug 986365 - Crash in supplicant because of closing supplicant while waiting for event. r=chulee, a=1.3+
Bug 993821 - [Wifi] Event thread is blocked in WaitForEvent caused wifi stay in searching state. r=chulee, a=1.4+