dev-libs/weston: Building test is broken in portage, disable for now. Bump to 1.3.1
dev-libs/wayland-1.3.0: bump
x11-base/xorg-drivers: add freedreno to VIDEO_CARDS
media-libs/mesa: Enable tests.
dev-libs/weston: improve weston USE and deps
x11-proto/xproto: sync keywords with portage
media-libs/mesa: make llvm-shared-libs optional

This allows users to work around incomplete RPATH in i915g until a proper fix is implemented.
Bugzilla: https://bugs.gentoo.org/show_bug.cgi?id=488216
x11-base/xorg-server: sync mesa dependency with portage for bug #492852.
x11-libs/pixman: Add ssse3 USE flag.
media-libs/mesa: drop llvm-shared-libs requirement for opencl.
radeontop: version bump, fix deps, add USE nls, respect CC, do not strip by default

Package-Manager: portage-2.2.7
x11-libs/libXft: fixed compilation 2.3.1-r1 with freetype 2.5.1
x11-proto/glproto: sync keywords with portage
x11-base/xorg-server: raise glproto dependency
x11-proto/glproto: bump 1.4.17
Remove package versions that are in portage now.
x11-base/xorg-server: update to latest xdm init script.
dev-libs/wayland: bump 1.3.91, switch to git-r3

Package-Manager: portage-2.2.7
dev-libs/weston: bump 1.3.91, remove tablet USE (broken and removed), switch to git-r3
x11-drivers/ati-drivers: bump multilib version of the ebuild