Implement Firefox process start/management

[njasm]

when NewSession is called, we should check if a firefox Instance is already running and try to connect to it, else we should try to find and start the processa and manage it. when ending a session we should also end the process if it was started by us.

[dvn0]

+1 on this. I'll look at implementing if I find some time. Currently trying to figure out a good reliable way to do this. Having issues with killing the process reliably.

[njasm]

@dvn0 if you have some code for this feature availiable online i'll try to help. I'm also really short on time atm to do it myself