More opt.[ch] cleanup in the new commands

src/salloc/opt.c

src/salloc/opt.h

src/salloc/salloc.c

src/sattach/opt.c

src/sattach/opt.h

src/sattach/sattach.c

src/sbatch/opt.c

src/sbatch/opt.h

src/sbatch/sbatch.c

src/slaunch/opt.c

src/slaunch/opt.h

src/slaunch/slaunch.c