Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170424-1' into staging

Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170424-1' into staging

fix display update races, part one.
add xres + yres properties to qxl and virtio.
misc fixes and cleanups.

# gpg: Signature made Mon 24 Apr 2017 13:14:49 BST
# gpg:                using RSA key 0x4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <[email protected]>"
# gpg:                 aka "Gerd Hoffmann <[email protected]>"
# gpg:                 aka "Gerd Hoffmann (private) <[email protected]>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/pull-vga-20170424-1:
  virtio-gpu: add xres and yres properties
  qxl: add xres and yres properties
  vmsvga: fix vmsvga_update_display
  g364fb: make display updates thread safe
  exynos: make display updates thread safe
  framebuffer: make display updates thread safe
  vga: make display updates thread safe.
  vga: add vga_scanline_invalidated helper
  memory: add support getting and using a dirty bitmap copy.
  bitmap: add bitmap_copy_and_clear_atomic
  virtio-gpu: replace PIXMAN_* by PIXMAN_BE_*
  console: add same displaychangelistener registration pre-condition
  console: add same surface replace pre-condition

Signed-off-by: Peter Maydell <[email protected]>