clush has a rich set of output handlers defined in Clush.py. Instead of reimplement them for an external tool, it would be nice to be able to use them directly. Unfortunately, the error messages currently hard-code clush: as a prefix.

I would propose making the prefix configurable, and potentially moving the OutputHandlers into either Display.py or their own new file.

I'm happy to implement and open a PR, but I wanted to get some consensus before starting work. Thoughts?