while testing for termination.

The slurmd build no longer includes mgr.c, task.c, slurmd_job.c, io.c,
fname.c, ulimits.c, and pdebug.c since these are only needed in the new
slurmd_step binary.

Both slurmd and slurmd_step daemons now include slurmd_step_init.c which
has the pack/unpack functions used at slurmd_step startup time.

The run_script function is moved to its own file run_script.c since both
daemons need it at the moment.  This is candidate for moving to src/common.

Broke slurmd_step.c up into functions in preparation for future code
additions.

read_proc.c does not appear to be used anywhere, so that might
be another file that could be removed from the slurmd build.

 first one arrived  when first terminate was being processed).
Check if a job's credential has been revoked before launching 
 additional tasks.

and restructure some code to comply with linux kernel programming standard.

with a DRAIN flag. COMPLETING state is changed to a COMPLETING flag. 

In the slurmd_step program, after stderr is connected back to srun
no debuggin levels higher than debug3 are written to stderr.  The stdio
code will avoid using debug3 or lower in critical sections that could
result in circular generation of network traffic.

and correct --attach and --join descriptions

its relationship to small bglblocks.

the initial client eio object and later "srun --attach" objects are handled
due to the caching.

Modifications to the eio engine to move the List of eio_obj_t into the
opaque eio_handle_t.  New eio calls "eio_new_initial_obj" and
"eio_new_obj", both of which add an eio_obj_t to the eio_handle_t's internal
object List.  However, only the later function is safe to call when
the eio mainloop is running.

Also caught in this commit is some initial code to implement the RPCs
REQUEST_TERMINATE_* and REQUEST_SIGNAL_*.