kes Implement console 'wait mount' command. Doesn't yet work.

kes  Implement timeout=nn on console 'wait mount timeout=nn' command.
kes  Break the do_swapping into do_unload, do_swapping, and
     do_load.  It is much more logical that way.
kes  Implement a set_dcr_from_vol subroutine in acquire.c for
     reading volumes. This allows the dcr to be refreshed after being
     zapped when the wrong volume is mounted.
     This should fix bug #1126 -- During multiple tape restore, bacula
     does not ask for physical tape change, but rereads same tape