actually added cameras and skylights
gitignores
added TODO file
added triangle shape
added direct_mesh
fixed: building orthonormal base failed when major axis was negative
added PLY loader
added max_elem and abs_max_elem to util.hpp
added BVHMesh stub (no hierarchy yet)
added top-to-bottom hierarchy building to BVHMesh
removed EPSILON from Mesh intersection test.

This helps with triangles being skipped, hopefully doesn't break anything
minor modifications, os<<vec3 in mymath.hpp
added support for Debevec lightprobes
Merge branch 'mesh'
fixed: transform multiplication messed up inversion matrix
fixed rng artifacts in blocks: seed rng differently for every block
fixed bug in dielectric fresnel when ray came from inside the media
added custom malloc wrapper to set hard limit to memory usage
better memory management
commented out debug prints in scene loader