Construct entities / components in a completely data driven manner.

[dgavedissian]

Currently, the networking system relies in a fairly hacky "Entity Pipeline". Instead, this should probably be fully data driven so entities can be created dynamically without having to hard code anything. This would be useful for networking.

Perhaps, networking should replace the Entity Pipeline with some kind of static registration function that provides a function called to "create" an instance of that object when replicating it.