As previously mentioned, focus is now moving a bit away from the editor and back to the content side of things, as I have to get more of an idea what I want before I can figure out how to implement it. Anyway, there has still been a bit of editor progress, the navgraph tools got a little more improvments, a little compatibilty fix for older Gtkmm was added and some classes where split into seperate files. Most importantly however the layer tree got rolled back to a flat layer list, as the tree was just making things to complicated and error prone without actually providing any real advantage. This breaks the file format a bit, but the sectors in SVN have already been properly converted. Another new thing today is improved drag&drop, you can now drag stuff directorly from the ObjectSelector into Gimp, reload in the ObjectSelector is hooked up as well, meaning you no longer need to leave the editor to update graphics or mess around with a file select dialog.
I also replaced the COPYING file, it no longer contains the full GPLv3 license text, but instead an explanation which files fall under which license along with links to the licenses, namely GPLv3 and CC-by-sa.