Fixed ConfigWorldGenScreen

The displayed properties are now correctly updated on selection change
events.
Persistent storage of world generation params
Assign world generator configs to world entity
Merge branch 'develop' of github.com:MovingBlocks/Terasology into develop
Convert json config data to module components
Use configured json parser for module data config params
Merge pull request #997 from msteiger/persistent

Persistent storage of world generation params