Can no longer automatically infer size of resized images

[ExpHP]

You used to be able to do the following:

• Supply both an ANM and directory image source: truanm c -i original.anm -i images/ ...
• ...where images/ contains an image of a size that differs from the texture dimensions of its entry in original.anm...
• ...without needing to specify img_width/img_height.

Basically, the PNG dimensions would override those in the ANM entry, and the use case was to make life easier for people who need to make a sprite bigger than would fit in the original texture by not requiring them to write the new dimensions. There used to be a test case for this here.

This functionality is no longer compatible with the new correct behavior for handling subregion extraction and compilation (see #67). You must manually specify img_width/img_height if you are resizing an image, otherwise truth will interpret the offset/size from the ANM file as reading a region of the PNG.

Perhaps img_width: "auto" could at some point be added to restore this functionality.