[project @ 1999-11-11 17:19:15 by simonmar]

Re-instate interrupted stuff.  If the scheduler finds the interrupted
flag to be set, it calls deleteThread() on all the runnable and
blocked threads, wakes up any main thread clients that were waiting,
and then either

	(a) returns, in the UP case
	(b) waits for more work, in the SMP case.