A few more breaks
Add support for reading PNGs.
Not that anything is being done with them yet, but it provides the
functionality. This code isn't as well documented as I'd like it to be, since
there's a decent chance that there's a better way to go about this that I'm
not seeing. For now though, I'll just get something that runs, then clean the
code up after. Since this is basically the reverse of the save function, I
looked at that code a lot, and I'm honestly not too happy with it, so there's
yet another todo.