Merge branch 'test4issue373' into 373

* test4issue373:
  Add log output for failed message queueing in test due to disconnect
  Add trace output to verify that reducing the tcp send buffer forces TCPSOCKET_INTERRUPTED
  Reduce the tcp snd buffer to provocate issue #385
  Move the evaluation of the not freed memory _after_ call of MQTTAsync_destroy()
  Fix Windows build of test_issue373 and increase number of iterations
  Consider any not freed memory as test failure
  Modified number of connect iterations and messages send per second
  Moved the decrement of pendingMessageCnt to another call back function
  Add test for issue #373 and #385
  Add skeleton of test_issue373