Don't free memory from InnoDB at exit (as this may be done before other threads are finnished)


include/my_pthread.h:
  Added missing prototypes
innobase/srv/srv0start.c:
  Don't free memory at exit (as this may be done before other threads are finnished)
mysys/mf_iocache.c:
  Cleanup (Don't rely on return value from mutex_unlock())