Don't block for output in non-blocking mode if clists run out.
Don't block for output in non-blocking mode if clists run out.

Remove an unnecessary test (if the output queue is above high water
then it is nonempty).

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase