Programmatically set SIGKILL timeout

[davidw]

We need a timeout that is more than 5 seconds. It'd be nice to make this configurable - possibly on a per-process level.

[OvermindDL1]

I am running things that take more than 5 seconds to cleanup, and when they do not clean up properly it corrupts their entire state due to poor programming on their part. Do need this to be configurable.

[saleyn]

This feature is implemented in the master HEAD via {kill_timeout, Seconds::integer()} command option.

[davidw]

Thank you!