MB for memory and bb.

Bug 1783

select/cray - Initiate step node health check at start of step termination
    rather than after application completely ends so that NHC can capture
    information about hung (non-killable) processes.
bug 2192

the message.  This was needed for sbcast or srun --bcast since the
tree width is different than the default.

Bug 2512

Make default compression vary based on library availability.

A node's CPULoad was getting reset to NoVal on reconfiguration.
This change preserves the old value, which can fix a possible
race condition with respect to test4.13

Calling functions all moved to src/bcast/

power/cray - Fix bug introduced in 15.08.10 preventin operation in many
    cases.
bug 2628

Was printing integer using %u format

burst_buffer/cray - Fix for script creating or deleting persistent buffer
    would fail "paths" operation and hold the job.
bug 2624

and it doesn't meet basic requirements.

Test previously failed with heterogeous nodes (i.e. different
core counts on different nodes).
bug 2597

We know it is in 1.7.1 but not in 1.3.0

tree_msg_to_stepds() which does the same thing.

nodes not able to contact.

Bug 2431

This reverts commit 2243bf33.

Conflicts:
	src/plugins/burst_buffer/cray/burst_buffer_cray.c
	src/plugins/select/cons_res/select_cons_res.c

The gprof tool is showing most time is being consumed by the bit_test()
  function as called from the select plugin, which in turn was called
  by the backfill scheduler. These changes replace the for loop end-points.
  Previous logic tested for all possible nodes. The new logic identifes
  the first and last bit set in the node bitmap and uses those end-points
  instead. Node the logic to find the first and last bits set starts off
  with a word-based search (testing for a 64-bit zero value rather than
  testing each individual bit). The net result is a small performance
  improvement.
bug 2588