Mostly minor stuff and polish today, the ObjectTree class got renamed into LayerManager, FileWriter writes things a little more Lisp-like, the Open, Save, SaveAs functions now behave more normal, giving you overwrite warnings, starting in the right directory and such, the Tabs now contain proper filenames and RecentFile handling is integrated as well. The output to stdout got a little cleaned up and some of it got redirected to the statusbar. Also fixed a crash that happened when objects got parented to themselves, leading to an endless loop.
On the levels/graphics side of things, there was a little cleanup as well, the trainstation.wst and mine.wst sectors got split into layers and a new sector worker.wst got created. Also the trainstation got some improved trains, which however are a little broken due to parenting not being properly loaded. The new layer systems is quite nice to work with so far, a toggle function that limits editing to the current layer is however missing.