Started work on acceleration structure - heavily unfinished yet.
BSPTree construction implemented. Todo: Reasonable tree intersection.
BSP-Accelerator finally working. Very slow with a large MAX_DEPTH... Todo: Change split axis in each iteration.
Acceleration structure there and working. Thanks, @panmari for your heroness!
Added dragon object. Test-scene takes about 1200ms to render.
Platform independent file-loading for @panmari :-D