equivalents. For consistency make them return integer values (like before)
that are not valid characters (e.g. 0x100). This avoid the use of single
character values that we might want to preserve.

Job's priority would be reset if it could not be immediately scheduled
AND if the best-fit node selection picked a DOWN node.

client and server are both reusing ports that match a defunct socket
connection in TIME_WAIT state. On this failure, we select a new random
port number and try again to connect.
(gnats:253)

from 2 to 5 seconds for slow tdev.

  - changed defs of HAVE_LIBELAN3 to HAVE_ELAN

   Elan3 and Elan4. Also allow old Elan3 module to work exactly
   the same as before.

   libelanctrl or libelan3

Send multiple SIGALRMs if needed and deal with possible abort of
a thread.