GPL3 for everything except:
	- tools/texture_packer/TexturePacker.[h|cpp] from John W. Ratcliff, MIT license.
	- api/windows/dirent.[h|c] from Kevlin Henney.
	- libs used (see their own LICENSE file):
		- libs/glm
		- libs/enet
		- libs/libpng
		- libs/sqlite3
		- libs/tinyxml2
		- libs/tremor

