#6069: Remove md4 model support.
Merge remote-tracking branch 'ioquake3/master'

Conflicts:
	code/renderergl1/tr_animation.c
	code/renderergl1/tr_local.h
	code/renderergl1/tr_model.c
	code/renderergl2/tr_animation.c
	code/renderergl2/tr_local.h
	code/renderergl2/tr_model.c