* src/common/clock.cxx (add_alarm): Tweak last change to allow alarm order for identical alarms to be the same as it used to be. * src/common/clock.cxx (add_alarm): Fix bug resulting in alarms not being added at all if a lower triggered alarm already exists. Reported by Christoph Csebits. Also fix bug when alarm is entered for the same time as tail. These bugs only apply for CYGIMP_KERNEL_COUNTERS_SORT_LIST enabled. * doc/kernel.sgml: document that order of callback for alarms at identical times is unspecified.