Get rid of some really annoying legacy Tcl commands in the core. As long as we don't have any LED indicators in the console window, show an error for audio dropouts instead. Also get rid of some debugging messages in the pddp.

 *fixed typo in the m_sched.c that caused problems with pthread, merged some of the upstream code cleanup

 *fixed regression caused by the Haswell/Skylake CPU pthread improvement as reported by Antonio Roberts

*updated locking mechanism to prevent multiple locks or unlocks in a row, which in turn causes crashes on newer Intel processors.

added additional check to make sure clock_unset is not trying to unset something that just happened (may require further testing, based on one gdb segfault log)