Merge remote-tracking branch 'kraxel/tags/pull-ui-20170512-1' into staging

Merge remote-tracking branch 'kraxel/tags/pull-ui-20170512-1' into staging

ui: add egl-headless
ui: some vnc cleanups
ui: absolute events for input-linux

# gpg: Signature made Fri 12 May 2017 12:50:07 PM BST
# gpg:                using RSA key 0x4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* kraxel/tags/pull-ui-20170512-1:
  vnc: replace hweight_long() with ctpopl()
  vnc: simple clean up
  opengl: add egl-headless display
  egl: explicitly ask for core context
  egl-helpers: add missing error check
  egl-helpers: fix display init for x11
  egl-helpers: drop support for gles and debug logging
  virtio-gpu: move virtio_gpu_gl_block
  ui: input-linux: Add absolute event support
  ui: Support non-zero minimum values for absolute input axes

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>