This isn't optimal, but on the short term we'll clone the page editor to use as a block editor, and probably a layout editor as well. Eventually, these should all probably just be switches onto a single editor instance. Decided to put the layout_mid into the item table directory rather than re-use resource_id, so that we can still have pages attached to different resources like photos and events and stuff. The block editor is far from finished, at this point I've only cloned it and changed the name and type of item it looks for.