Changed, Things mode: things are now rendered with a bit of transparency, so things beneath other things are now visible.
Fixed, Things mode: in some cases it was impossible to highlight a thing beneath other thing when their positions were the same.
Changed, 2D modes: changed thing bounding box and arrow image.
Fixed, cosmetic, 2D modes: in some cases thing arrows were rendered bigger than thing bounding boxes.
Replaced all doubles with floats.
Script Editor:
Navigator drop-down now updates automatically.
Navigator drop-down now also works for external files.
Added Navigator drop-down support for Decorate and Modeldef.
