Config Shorthands via entry_points

The canonical way of having plugins for Python is to use `setuptools` `entry_points`. This could replace the currently hardcoded `nicks` in `interface.py`, and allow generalising the tool.

Suggested entry points:

* `<libname>.core` for e.g. telegraf backend, loggers etc.
* `<libname>.xrootd` for specific elements, e.g. the ALICE ApMon