Check if PID is still active

[matt-truslove]

Is there any way you can add the ability to see whether a PID no longer exists? Colouring the PIDs a different colour maybe? Should be efficient if you poll /proc

[boomskats]

Should be doable for the local node, yeah. Might have a play with it this w/e

[cj13579]

Better late than never, I've made a crude implementation of this which works nicely for single node deployments but could be misleading in multi machine setups.