Fixes and additions:
- Made the demo project a whole lot more interesting
- Implemented the editor wish list item: Ability to move trees between collections
- Various tweaks to the editor UI
- Fixed a ton of bugs in the compiler
- Fixed the following editor bugs from the bug list:
- Not able to delete collections from library
- Not able to delete trees from library
- Not able to rename collections from library
- Not able to rename trees from library
- Missing “tree has been changed, save changes?” dialog