Introducing dynamic BlockFamily creation. New BlockFamily types can be introduced in mods using a RegisterBlockFamilyFactory annotation.
Fix for health component being saved after the entity removes it.
Merge branch 'blockFamilyMultiplayer' of git@github.com:MarcinSc/Terasology.git into multiplayer-blockfamily
Some slight cleanup
* Moved the json merge function into a utility class.
* Cleaned up the collection and providing of categories to the families
Refactored the methods around building the world atlas into a separate class.