Mesa without OpenGL and related fixes

Sometimes this job leads to strange things. Today I've been building mesa without any opengl.

The issue was that vulkan needs vulkan drivers (from mesa) to work, making the vulkan recipe essentially require opengl distro feature.

Mesa can be instructed to build only the vulkan bits so that's what I did. Also tried to make the dependencies between packageconfigs clearer since the build system is quite complex.

I've tried my best to ensure no unintended PACKAGECONFIG changes happen.

Thanks,
Jussi

The following changes since commit cd26fc143bbfd948795c2e65a577f89627a4f841:

devtool: deploy-target: Support stripped libs and execs (2017-08-27 22:32:00 +0100)

are available in the git repository at:

git://git.yoctoproject.org/poky-contrib jku/mesa-without-opengl
http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=jku/mesa-without-opengl

Jussi Kukkonen (3):
mesa: Support building without opengl
vulkan: rrecommended drivers unconditionally
xserver-xorg: Enable xwayland only with opengl

 .../0001-configure.ac-Always-check-for-expat.patch | 51 ++++++++++++++++++++++
 meta/recipes-graphics/mesa/mesa.inc                | 23 +++++++---
 meta/recipes-graphics/mesa/mesa_17.1.7.bb          |  1 +
 meta/recipes-graphics/vulkan/vulkan_1.0.51.0.bb    |  3 +-
 .../recipes-graphics/xorg-xserver/xserver-xorg.inc |  2 +-
 5 files changed, 70 insertions(+), 10 deletions(-)
 create mode 100644 meta/recipes-graphics/mesa/files/0001-configure.ac-Always-check-for-expat.patch

2.1.4