finished implementation of node_registration_status message that the nodes sent to the controller when they come up

Added specific defined errorcodes that will be returned in the SLURM_RC_MESSAGE and formatted the slurm_protocol_pack file

Fixed some code for zero size memory allocates, and zero size messages.

Changed backup controller to "lx01" in slurm.conf2
Changed remaing malloc/free functions to xmalloc/xfree.

buffers that are pre-build by slurmctl, using the old inline pack, and for this reason
did not use the assert checked functions

node info conversion

I am implementing the new comm layer in all the api functions
added sockopt parameter SO_REUSEADDR to eliminate socket turn around time during debug.

slurm_protocol_errno.h provides a default place for slurm specific error definitions until Jim completes his general errno implementation

Cleaned up comm layer , this never ends :)
added pack and unpack routines for new communcations paradigm

cleaned up packing and upacking for job_desc
added src/common/log.h include to resolve link warnings

inclusion of autoconf socket #ifdefs

fixed added set_slurm_addres_hton to slurm_protocol_util.c

slurm_protocol_api.c			contains the programers interface.
slurm_protocol_interface.h 		defines the lower layer interface.
slurm_protocol_pack.c			packs messages.
slurm_protocol_util.c			contains utility functions used by the protocol