diamondd: Remember to catch SIGUSR1 in control thread
diamondd: Remember to catch SIGUSR1 in control thread

Worker threads use SIGUSR1 to initiate search shutdown, so remember to
catch it.

cmusatyalab/opendiamond,cmusatyalab/opendiamond,cmusatyalab/opendiamond,cmusatyalab/opendiamond,cmusatyalab/opendiamond