Overwriting _size leads to the bitmap being the wrong length.

CID 160063.

The safe_unpackstr_xmalloc() call could jump to unpack_error,
which would leak memory allocated for bitmap. Allocate only after
the unpackstr has succeeded.

Coverity 160092 (+ more due to macro expansion leading to repeats).

Code would return NO_VAL if the requested frequency was greater than
the highest available.

While here improve the errors printed to the slurmstepd log location,
and change the initial check against nfreq to test for zero. (Rather
than (uint8_t) NO_VAL which it could never be set to.)

Bug 3335.

Bug 2508

If job is allocated nodes which are powered down, then reset job start time
    when the nodes are ready and do not charge the job for power up time.
bug 3411

No changes in logic

Modify get_my_user_name to return a FAILURE if the user_name cannot
be determined, as was handled inconsistently.

the function.

Bug 3312 and 3332

jobid and stepid to be used if needing to kill job because it hadn't started yet.

Add logic to monitor Uncorrectable Memory Errors (UME) and notify
  active jobs in case they run for a while afterwards. This copies
  logic from knl_generic to knl_cray. There may be a different UME
  monitoring system for Cray systems in the future. The original
  knl_generic development is in commit 56ff27da
bug 3341

Replaced identical code in tests with a call to this proc.
Also replace instances of code getting uid with a call to the
global proc get_my_uid / get_my_nuid.

bug 3390

see bug 3166

ensure eio objects get explicitly shutdown when
eio_handle_mainloop exits. currently depending on
whether the order the eio_handle_mainloop and
eio_signal_shutdown get called relative to each other

when stepd is instructed to shut down the socket use
SHUT_RDWR instead of SHUT_RD. just using SHUT_RD can
cause srun to receive ECONNRESET if there's outstanding
data that's been sent to stepd that the task has not
read.

bug 3166

No change in logic

bug 3399

bug 3099

Improve logic from commit 1f8e8c9f

This reverts commit e92b49d3.

No functional change.

Fill the entire buffer, snprintf will always terminate with \0.

instead of also in the backfill scheduler.

PATH_MAX is used in many other places within the source without these
definitions; while technically optional in POSIX1.2008 I have not
seen anywhere that does not set it, and if such a system exists
it'll be needed elsewhere and the build system should handle it.

Also, POSIX1.2008 states this must be at least 1024, not 256
as used here.

Avoid allocating resources to a job in the event that its run time
    plus boot time (if needed) extent into an advanced reservation.
Note that if resources have not yet been selected (e.g. determining
  availability of licenses or burst buffers with respect to advanced
  reservations) then assume a reboot will be required.
bug 3360