virtio-gpu: add 3d rendering support using virgl, misc fixes.
ui/gtk: add opengl context and scanout support (for virtio-gpu).

# gpg: Signature made Thu 08 Oct 2015 10:35:39 BST using RSA key ID D3E87138
# 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>"

* remotes/kraxel/tags/pull-virgl-20151008-1:
  gtk/opengl: add opengl context and scanout support (GtkGLArea)
  gtk/opengl: add opengl context and scanout support (egl)
  opengl: add egl-context.[ch] helpers
  virtio-gpu: add cursor update tracepoint
  virtio-gpu: add 3d mode and virgl rendering support.
  virtio-gpu: update headers for virgl/3d
  virtio-gpu: change licence from GPLv2 to GPLv2+
  virtio-gpu: move iov free to virtio_gpu_cleanup_mapping_iov
  ui/console: add opengl context and scanout support interfaces.
  sdl2: stop flickering
  shaders: initialize vertexes once

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>