o Fix locking bugs in slurmd due to fork from threaded app:

  - install atfork handlers in slurmd to protect against fork-critical
    code (gethostbyaddr and list_*)
  - do not bother freeing slurm credential context
 o Fix small bug in save_cred_state
 o Log more errors in slurmd manger and session mangers
 o change setproctitle and logfile prefix for NOALLOC jobs