Add slurm_addr to node record, set values and send credential revoke.

2- finished adding the job_step message stuff...

fixed launch_task_response msg
added slurm_protocol and slurmd errnos to slurm_errno.h
added print_slurm_addr to src/common/slurm_protocol_api.c
added print_slurm_credential to src/common/slurm_protocol_util.c
cleaned up debug printing and error reporting for src/slurmd/shmem_struct.c
more cleanup
etc

added a few comments and slurm_protocol_errno entries.
More little code cleanup

2- changed a typedef for step_spec ot reflect changes in slurm_protocol_defs

2- Cleaned up the .h file

RPC is used to distinguish it from the SHUTDOWN RPC comming from scontrol.
It was added to deal with a race condition.
Kevin's change in where pthread_create occurs and how the RPC is
processed is now the default (#ifdef kevins_way removed).
Added limit on the thread count before going to non-threaded RPCs
(see MAX_THREAD_COUNT in controller.c).

RPC is used to distinguish it from the SHUTDOWN RPC comming from scontrol.
It was added to deal with a race condition.

SIGTERM (shutdown).

Added slurm_shutdown RPC.

Addes slurm_shutdown RPC.