conditionalize "hwptr went backwards" messages
conditionalize "hwptr went backwards" messages

modify default buffer size heuristic to not max out at 4k.  mpg123 should now
behave better under load.

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