Commit Briefs
Add the #goo to allow use in C++.
Silence a few more warnings. Strip down the mkfiles more. Fix bug in X11 mouse handling, note groups.
Lib9.h updated to support plumber from Caerwyn Jones.
(New lib9.h expected soon.)
Various tweaks to make things run on Mac OS.
The main change is the use of pthread to implement ffork.