Enhancement: Add exit arg to main func

[medic8601]

Currently it is not possible to execute pabot as a child process since it force exits at completion.

The run_cli function from robot module provides an exit arg that is defaulted to True. When True, the process will exit but if False it will return the exit code. This allows a user to launch the main function directly from a parent Python script that would perform pre-testing and post-testing actions.

[medic8601]

I just updated my fork and PR with the most recent updates from this project.

Any idea if this will be merged soon?

[mkorpela]

@medic8601 I'm very sorry but I've been heavily focused on other things for a long time.. This seems like a valid use case and I would be super happy to merge this.