Inject factory functions (scopes?)

[ferdinand-beyer]

A component may chose to dynamically obtain instances of a dependency.

Use case: Create a new Reitit router for every call in development.

Currently, this is possible by making the component instance a function, but this seems to complect two different things: Constructing an instance and deciding how to inject it.

[ferdinand-beyer]

During development, we might want some components to be started on every request, e.g. ring routes.

Partial restart of a system map?