Update autools stuff

There were remnants of an old way of doing things.  Also added the
bootstrap script.
Make variables and funcs static
Add ability to change the preemption period
Make upthread-juggle interrupt safe

Uses the new vcore-signal stuff just added to parlib.  It was actually
prootyped inline here, and then moved over there without ever committing
it on this side.
Set proper stack for main thread
Fix some spacing
Update test to more accurately show what we want

This test never terminates still, so I'll need to write one that does
for benchmarking, but you cna launhc a bunch of these guys in parallel
in different tabs and watch them all fight for cores to run all their
threads.  Pretty cool stuff.