-* Add in a middle image size, so thumbs -> medium -> full size
-* Allow to recreate galleries and use new captions (only resizing changed
- images) - mostly done, needs to be able to check and change based on
- the width specified then it'll be finished
-* Allow a fixed height to be specified instead or as well as a fixed width, in
- the latter case, resize to which ever fits the bounding box, but keep the
- aspect ratio.