Drone processes should not adopt SIGCHLD handler from parent (Perl)

[Bill Erickson]

Code in working => user/berick/perl-children-sigchld-default

From the commit:

Remove the special SIGCHLD handler applied to the parent/listener process from spawned child processes (drones) by setting child handler to DEFAULT. Otherwise, if an OpenSRF drone process spawns a sub-process, the drone will execute the SIGCHLD handler meant for the Listener when the sub-process dies, wherein hijinks ensue.

Basically, $SIG{CHLD} = 'DEFAULT';