Allow core based reservation use with nodelist requested.

Core based reservations in an asymmetric cluster should use a nodelist
with a corecnt array which overcomes the last limitation when using
these kind of reservations.
Next work will be to allow updating a core based reseravtion.
Changes needed to asymetric core reservation for clean build

Make core reservation test a bit more flexible in terms of node names

Fix arithmetic for core reservation count return for old RPCs
Update NEWS and RELEASE_NOTES

Remove trailing spaces from recent scontrol man page changes