JobMonitor Port and Job Native Specifications.

[baluyotraf]

For systems with that can access a limited range of ports, I think it would be nice to let the user specify the port for the JobMonitor

Also exposing the native specifications should allow users to add advance options on their jobs.

I can make a PR for it as I currently implemented those on the gripmap fork in my repository.

[mulhod]

That would be great! I have a very small PR open for exposing the gpu resource, but it would be great to have additional native specifications.