JBIDE-18094

The prompter code is already used by other core/ui interactions. I'd welcome a review with a more thought out solution. As of now, basically, anyone can add a prompt handler with an event code.    So the UI is in charge of adding prompthandlers for specific event codes. 

This also allows fuse to register different prompt-handlers to their own prompter for the same event if they need different behavior, or delegate behavior to the default if they don't wish to override. 

The other thing is that your solution would basically require a new interface for each prompt type, which could get pretty burdensome. It also means that if Fuse wanted to customize HOW hte prompt is handled (say with a different return type) then they'd need a different interface. 

Again, I welcome  areview of the core/ui interaction if you have time to walk through it. But Fuse is already using this logic for prompters, so any changes would need to be coordinated with them.