Refactored some packages and corrected some module access:
 - Renamed org.terasology.copyMetadata to org.terasology.reflection. Moved the classMetadata specific parts under a metadata subpackage.
 - Moved the CoreRegistry, In and Share annotations into org.terasology.registry.  A deprecated copy of the In and Share annotations was left behind to allow modules to continue to work with those (anyone using CoreRegistry directly is out of luck, sorry).
 - Centralised injection and sharing code, and granted it required permissions.
 - Moved TextureRegion and SubTexture under org.terasology.rendering.assets.texture, adding it to the API.