Various updates for new slurmctld/dynalloc plugin

1. Removed the job_submit and job_modify functions from the plugin, they are not required for the "slurmctld" plugin type
2. Renamed the new parameter from "JobSubmitDynAllocPort" to "DynAllocPort" and renamed the variable (You need to change this in your slurm.conf file)
3. Added logic so you can see the DynAllocPort value using "scontrol show config" or "sview"
4. I made some minor formatting changes, mostly for lines that were too long
5. Added #ifdef to the msg.h header file
6. Changed the #ifdef variables in the header files to start with "DYNALLOC_", perhaps not needed, but it should safer, especiallly with some common names like "INFO_H"
7. I re-wrote much of info.c. There was no need to get a copy of the node information and process the copy. We can just work directly with the data structures.