Objective-C thr-posix bugs and additions.

[Chris Ball]

I was implementing lockBeforeDate in gnustep when I noticed that the 
trylock code was broken in thr-posix.c.  I decided to carefully go
through the file since I had previously found and fixed a bug in
mutex deallocation.  I found that the returns were inconsistant
with what was returned in the other thr-* subsystems, the type
of thread created was not correct for how objective-c threads are 
used and that the thread priority functions were not implemented.

I quickly tested the changes and everything seems to work ok now.

ChangeLog Entry:

Fri Oct 8 11:58:12 PDT 1999   Chris Ball <cball@fmco.com>

	* thr-posix.c (*): fixed returns, added *_priority, changed thread type.

Attached: thr-posix.c   - the new version of the file
	   thr-posix.dif - the diff -c3p output

	Chris.