Merge remote-tracking branch 'remotes/kraxel/tags/pull-ui-20160928-1' into staging

ui: console+vnc fixes, switch spice to pure opengl with gl=on.

# gpg: Signature made Wed 28 Sep 2016 11:57:35 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

* remotes/kraxel/tags/pull-ui-20160928-1:
  ui/vnc-enc-tight: remove switch and have single return
  spice/gl: render DisplaySurface via opengl
  console: track gl_block state in QemuConsole
  console: skip same-size resize

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