Casc 200 rebasefail

This pull request works on CASC-200.  Please ignore the previous pull request (I'll close it) as I accidentally re-based a remote branch which you cannot do and in the process made additional changes :-(

This introduces a few things:
1. Configuration strategies
2. Configuration keys
3. a simple Protocol enum to separate protocol stuff from configuration

I realized there are a few javadocs I need to fix.
```MUST NOT BE NULL```: you could add check on that in the constructor, couldn't you?