Rewrite to remove dependence on rendezvous and its bizarre

data structures.  Makes it easier to use pthreads too.
Still need to add code for non-pthreads systems.

Just a checkpoint to switch work to another machine.

src/libthread/tprimes.c

@@ -41,6 +41,7 @@ threadmain(int argc, char **argv)
 	int i;
 	Channel *c;
 
+malloc(10);
 	ARGBEGIN{
 	case 'D':
 		_threaddebuglevel = atoi(ARGF());