Added updating to structures and islands:
1. Browse to the thing (structure/island) you want to update, push "Set Ready To Update"
2. Load the thing/edit it/etc.
3. Press Workshop Upload...
4. Update Island/Structure is a button, it should be available aka not disabled.
[It'll list the item ID, and the original item name. If the description was blank, it'll copy the description from the item you're about to update.]
Fixed not being able to upload islands with workshop structures on them