callers to better handle and report errors from this function. Also
update all callers to use new calling style. Update call site in
plugstack.c to report error using plugin_strerror(). Other callers
ignore errors as before.

 * Fix other gratuitous whitespace use that didn't conform to SLURM style

spank_err_t type.

Certain SPANK items that are available in local or allocator context
may not be available until after cmdline options have been processed,
or after a job has been allocated. Return ESPANK_NOT_AVAIL to indicate
to plugins that this is the case.

This patch fixes a potential segfault if SPANK plugins call spank_get_item
for these items from early callbacks such as spank_init.

    nodes are configured in multiple leaf switches.

fix for reservations to create new entries in the database when something about nodes or cpus or flags change

  possibly a configuration error.

    launch tasks).

notify if the user or node_prefix has changed things aren't going to work correctly in the bluegene plugin

display a reservation's duration