rendering dummy billboards
added node billboard shader
correct orientation for billboards
introduced mapped buffer updates
shading of node billboards
use hot and cold vbos for billboards
multiple lights, single draw pass
replaced node meshes with billboards
avoid unnecessary computations in InitBillboards
ignoring annoying program outputs
addd material colors
fixed compare function
Revert "instanced rendering"

This reverts commit 0dcb3959575a43ae10cb84b6462e558c8c26b3eb.

Conflicts:
	res/Shaders/lit_pass1.frag
	res/Shaders/lit_pass1.vert
	src/Nubuck/renderer/renderer.cpp
undo instanced rendering