[WIP] #1248: Replace Zf\Config with Serializer-based config

In this commit I have placed the groundwork for replacing
the Zend\Config component with a JMS Serializer based solution.
This will enable us to show and document the configuration files
because they are solid objects.

Remaining TODOs:

- [ ] DocBlock all the things; the classes and especially configuration should have DocBlocks explaining their function
- [ ] Remove the old configuration
- [ ] Write unit tests
- [ ] Test, test and test even more