[WIP] I removed relative constructors and added more implementation.

Those constructors for IDedType and IDedTypeWithData were just making
things more complicated, especially with the way entities are now
subdivided. Therefore, I got rid of them; types should now be declared with
their I.D. and data value given explicitly in the constructor.

Also, I continued implementing Entity stuff for Animal and other classes.

Signed-off-by: REALDrummer <conman.davey@gmail.com>