Redesign configuration system

[BasLee]

Project specific configuration files contain too much functionality. At the moment the configuration files renders the app, instead of the app rendering the configuration.

We should try to simplify project configuration:

• configuration should primarily consist of primitives like boolean, number and string values
• move 'configuration functionality' to separate, reusable components that can be enabled by config properties
• project specific components (e.g. menu, footer, info page, etc.) should be rendered by the app (and not vice versa)

[svandaalen]

Currently, the router is also configured in the project configuration. This configuration of the routes should also be refactored, because in the current implementation it only allows for an arbirtrary number of routes and components. This causes problems when a project requires more routes or more components to be rendered.