Added sched_setscheduler()/sched_getscheduler()
merge upstream
Use ifdef _POSIX_PRIORITY_SCHEDULING to protect sched_setscheduler
Added sched_setscheduler example/test
whitespace polish
whitespace polish
posix: tidy up rt_sched patches for merging.

* configure.ac (AC_CHECK_FUNCS): Add sched_getscheduler and
sched_setscheduler.
* ext/posix/posix.c (Psched_setscheduler, Psched_getscheduler):
Improve compilation guards to also require HAVE_SCHED_GETSCHEDULER
and HAVE_SCHED_SETSCHEDULER before exposing to Lua.
* examples/rt_sched.lua: Remove trailing tabs.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
Merge branch 'hjelmeland-f_sched_setscheduler'