Clean up code that redefines default leaves and default jungle leaves

Clean up code that redefines default leaves and default jungle leaves
(it was redefining more stuff than was necessary).  As a side effect,
this fixes a bug where non-plantlike leaves were using the wrong
textures in the inventory.

Remove all of the previous waving leaves changes as the shader that provides
that feature is about to change in a way that will break what I had here.

Clean up code that sets default drawtype and visual_scale of leaves