tests were change appropriately. This lets one fake a Linux cluster
without all of the BGL-specific logic.

and FastSchedule=0 and the cluster is heterogeneous.

Not critical, but a loose end in found in tracking memory leaks.

 uninitialized variables (thanks to valgrind).

  function on BGL.

  (was continuing search if job specified node count, but not geometry).

to switch_node_info_t.

No changes in logic.

listed twice.

used on Blue Gene systems. This avoid a redundant message for each and
every back-end node.

hostlist_ranged_string instead of one line per node.