Add ability to discover new jobs in a Jenkins multi-branch pipeline

[radarsh]

We use Jenkins to build each feature branch using the multi-branch pipeline. It would be great if this extension could automatically discover new branch jobs as and when they're created and/or deleted and reflect it on the UI accordingly.

I am envisaging a check box on the top level job or global settings which if enabled, it would cause the UI to react to new additions or deletions of sub jobs.