Run "register" when discovering plugins.

[tokejepsen]

Problem

Currently you can't generate multiple plugins with code.

Solution

When discovering plugins through environment variables, if register is found in a module then run it.

The use case is to generate multiple actions dynamically when the Launcher discovers its plugins.

[tokejepsen]

Turns out this behaviour is not suited for the core.

It diluted the methods in the core, and makes it harder to work with in other apps.