[HEADS UP] AMD Radeon HD 2xxx/3xxx/4xxx users to use 3D HW accel support

[Norikatsu Shigemura]

Hi Radeon HD users.

	I committed new Mesa3D and libdrm.  In this time, disabled, so
	to use new version, you should set WITHOUT_NOUVEAU on /etc/make.conf.

	Please see also /usr/ports/UPDATING and KNOBS.