[tcpnal]: rewrite the data out path.

[tcpnal]: rewrite the data out path.
  Get rid of pipe as a bridge between user threads and nal threads, which
  is not so efficient and don't work well in Cygwin. Now user thread might
  directly call into portals lib via lib_dispatch.

  2 issues remain:
  - sometimes during startup low level nal threads could run into endless
    waiting.
  - need more sycronous facilities to prevent race.