Use a Configuration to model the additional dependencies of each run

[shartte]

Use a Configuration to model the additional dependencies of each run, since configurations seem to be better at tracking task dependencies.

This does change syntax insofar as adding configurations will now look different.

It'll just be

runtime <configuration>

instead of

runtime configuration(<configuration>)

This is due to extending the internal configuration from the given configuration, and not converting the configuration into a Dependency first.

What could be discussed: Should the configuration be transitive by default? I think it should be, since that's how the normal runtime configuration would behave.