Config delegators

Closes #93 

Add some convenience functions to configurator which allow easier plugin creation without needing to write multiple delegator assignments by hand.

Also good for really reloading if need be, as this function can be used in the plugins' `init()` function.

This should allow for a more robust setup during route changes (i.e. changes of a config file). We'll keep an eye on this behavior to see if we really fixed the problem.