control - section Provides and Conflicts: Removing mesa stuff completely

This allows installing ffmpeg/libav-tools under Debian Stretch
See http://forum.xbian.org/thread-3927.html

build/content-tpl/DEBIAN/control

@@ -5,8 +5,8 @@ Section: firmware
 Essential: Yes
 Priority: optional
 Architecture: armhf
-Provides: libraspberrypi0, libraspberrypi-dev, libegl1-mesa (=8.0.0), libegl1-mesa-dev, libegl1-mesa-drivers, libgles2-mesa-dev, libgles2-mesa (=8.0.0)
+Provides: libraspberrypi0, libraspberrypi-dev
 Replaces: raspberrypi-artwork, raspberrypi-bootloader, libraspberrypi0, libraspberrypi-bin, libraspberrypi-dev, xbian-update (<=1.0-0.4)
-Conflicts: libraspberrypi0, raspberrypi-artwork, raspberrypi-bootloader, libraspberrypi0, libraspberrypi-bin, libraspberrypi-dev, xbian-package-firmware-6q, libegl1-mesa, libegl1-mesa-dev, libegl1-mesa-drivers, libgles2-mesa-dev, libgles2-mesa
+Conflicts: libraspberrypi0, raspberrypi-artwork, raspberrypi-bootloader, libraspberrypi0, libraspberrypi-bin, libraspberrypi-dev, xbian-package-firmware-6q
 Maintainer: mkreisl <development@xbian.org>
 Description: RPI firmware (RPI2 compatible)