Vessels: new textures
New grass(plant) and leaves textures
Revert "Fix fire blocking sunlight"

This reverts commit dcce6e97959647fd625c1ce219721c0b800f4938.
New flower textures
Default and flowers: only run on-generated functions in mgv6. Remove indev ore definitions
mgv6ongen > mgv6_ongen
Pass mapgen functions directly to 'register on generated'