Commands have been redone, giving them events to make them more useful.
Windows can now call close() to close themselves and go back to the previous window, applications no longer need to handle the event.
Back command has been removed in favor of windows implementing it themselves, but could leave a user stuck if not implemented right.
The UI should be fully navigable to an extent now, but the user list does not get refreshed after editing a user.
Files which hold a collection of files should be converted to a FileCollection, so that it can be displayed with the FileListUI.
MachineUI and UserUI have been renamed in favor of using them to edit as well.
Small other fixes and changes that shouldn't affect much.