Added VRAM support, improved texture stuff.
Merge branch 'master' of github.com:xerpi/ya2d

Conflicts:
	Makefile
	include/ya2d_main.h
	include/ya2d_png.h
	include/ya2d_texture.h
	source/main.c
	source/ya2d.c
	source/ya2d_png.c
	source/ya2d_texture.c
Added VRAM support. Improved texture functions.