functions. CPU_TPS is now only found in one Makefile.am and one
file, clocks.c.

Many of the uses are commented out or protected by TIMER_VERBOSE.
TIMER_VERBOSE no longer compiles, so these changes are untested
and just aim to guide the future...

Added a function to clean-up the links in a given space. Calling this before adding the new links solves the bug.

The waiting is done by testing readiness before waiting so there
is a window when nothing is waiting (probably near the end of the
sort), but we are still reading other stacks, which then get marked
as ready releasing the ready wait, so it's then just a timing game
as to whether the waiting wait is incremented in time... 99.999999%
of the time it is.

Make sure that the stack entries in which we will store new data are actually ready to receive data.

Matthieu Schaller authored Oct 27, 2015 and Peter W. Draper committed Oct 27, 2015

(cherry picked from commit 7131dc13 on master)