added Chris Provenzano's light-weight threading library.
from libpthread/README:
This pthread package is/will be based on the POSIX1003.4a Draft 7 pthread
standard, and Frank Mullers paper on signal handelling presented
at the Winter 93 USENIX conference.
It is currently being designed and written by me, Chris Provenzano.
All bug, comments, and questions can be sent me at either
proven@athena.mit.edu or proven@sun-lamp.cs.berkeley.edu
Please don't send questions, bugs or patches to any of the [FreeBSD] mailing
lists.
Copyright (c) 1993 Chris Provenzano. All rights reserved.
This product includes software developed by the Univeristy of California,
Berkeley and its contributors.