Added a new Lua library name to try loading with dlopen() in Lua
based plugins.

This continues the conversion of the cont_id from 32bit to 64bit,
 * updated slurm_container_find() to return u64 in order to match type of container ID;
 * updated slurm_proctrack_ops() to match the update of u32 -> u64 container ID in the
   slurm_container_xxx() functions,
 * miscellaneous type conversions from/to u64,
 * using "%"PRIu64"" for printing 64 bit.
Patch 01_proctrack-64-bit-conversion.diff from Gerrit Renker

This is the size of the container ID in the current SGI_JOB (PAGG)
library.

#include <slurm/slurm.h>
to 
#include "slurm/slurm.h"
so that the original source gets searched first

    support writing scheduling events to a separate log file.