fix a bug in KdNode::subdivide and remove some extra variables realtime.cc - use SW surface

new make infrastructure generalize floats to Floats, allow compiling as both double/float

naive color driven sub-sampling slightly optimized KdTree::nearest_intersection fixed bug in Box::intersect fixed stripes on spheres in spheres_ao.py (was caused by AO distance) new KdTree property: max_depth minor changes in realtime.py

new C++ demo: realtime.cc (real-time scene viewer using SDL) Quaternion, Camera::rotate and Camera::move replace all printf's with infomsg wrapper don't allocate memory in Raytracer::render, just blindly write to provided address don't creat Container object in Raytracer, let user do it

added Camera, currently w/o Python binding new #define option: OVERSAMPLING fixed all demos to work with new camera (they had inverted z axis)

new demo: dragon.py

fix last leak as reported by valgrind

add Raytracer::setThreads() resolved all memory leaks during rendering

C++ demos: prepare infrastructure, add spheres_shadow.cc rename Ray::a to Ray::o KdNode::shapes changed to pointer and added to union together with *children (to save memory)

replace Plane with axis-aligned Box (because infinite Plane is not usable with kd-tree) fix memory leak in KdTree::nearest_intersection rename BBox::R to BBox::H new file: common.h (Eps and Inf constants)