o shm.c : fix bug in semaphore initialization when lockfile exists

   but semaphore doesn't.
 o shm.c : added new _shm_sane() call that attempts to ensure shared memory is
   not improperly locked on attach.
 o slurmd.c : move more initialization code into slurmd_init()
 o slurmd.c : _reconfigure() now calls _read_config()