FreeBSD compiling fix.

[Øyvind Kolbu]

TODO task: 0x5b is quite easy to fix.
In Makefile.opts at line 186, add -phtread so the new 
line would like this: 
CFLAGS += -Wall -Winline -pthread
instead of
CFLAGS += -Wall -Winline

I'm trying to fix the sdl compilation problems as well.

-- 
Øyvind Kolbu