Wall clock limit increased for reg_small and reg_med queues

The maximum wall clock limit has been increased for the following two destination queues:

reg_small(1-255 nodes): from 24 to 48 hours

reg_med (256-1999 nodes): from 24 to 36 hours.

Jobs can not be submitted directly to these queues. Jobs of the appropriate size and routed automatically from the "regular" submission queue.