Implementing SCTP protocol support, and fix some warning.
SCTP multi-stream RPC service support.

DONE:
  * SCTP multi-stream RPC service support.

TODO:
  * SCTP send/receive.
  * SCTP client connection.
  * Potential crashes.
  * Memory leak.
SCTP multi-stream RPC client/service support.

DONE:
  * SCTP multi-stream RPC service support.
  * SCTP RPC client support.
  * Test cases.

TODO:
  * SCTP message based send/receive.
  * Potential crashes.
  * Memory leak.
  * Server keep connection even if client disconnected.
Avoid child process become zombie, and some code cleanup.

DONE:
  * SCTP multi-stream RPC service support.
  * SCTP RPC client support.
  * Test cases.

TODO:
  * SCTP message based send/receive.
  * Potential crashes.
  * Memory leak.
  * Server keep connection even if client disconnected.
  * Implement SCTP keep-alive.
Implement of RPC keep-alive, also detect abnormal disconnect from client.

    DONE:
      * SCTP multi-stream RPC service support.
      * SCTP RPC client support.
      * Implement RPC keep-alive for SCTP/TCP.
      * Test cases.

    TODO:
      * SCTP message based send/receive.
      * Potential crashes.
      * Memory leak.