Doorman manager child processing issue

[mfendeksilverstripe]

Doorman manager child processing issue

Problem

Using asynchronous queue runner has a flaw - when the manager process terminates, it also terminates all of its child processes. This is a mistake because there is a valid use case where manager process doesn't have any more work to do (no more jobs to start) but the child processes are still executing jobs.

Solution

Fix the shell command and prevent the manager process from killing of the child processes.

Fixed in #305