DMI tool thingy. Is able to do many things with DMI files.

As in title.

Is able to load and save every DMI in the BS12 repo except one (because it hasn't changed for four years and is still DMIv3).

Things it can do:
- verify: Load a DMI, do nothing with it
- diff: Load two DMIs, print a diff between them
- sort: Load a DMI, sort the icon_states into ASCIIbetical order, then save
- merge: Load three DMIs, merge A and B's changes from O into Out. Conflicts go into [Out].conflict.dmi
- extract: Load a DMI, extract a given frame/dir of a given icon_state to BMP format