Merge remote-tracking branch 'remotes/spice/tags/pull-spice-20150304-1' into staging

misc spice/qxl fixes.

# gpg: Signature made Wed Mar  4 13:57:42 2015 GMT 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/spice/tags/pull-spice-20150304-1:
  hmp: info spice: take out webdav
  hmp: info spice: Show string channel name
  qxl: drop update_displaychangelistener call for secondary qxl devices
  vga: refactor vram_size clamping and rounding
  qxl: refactor rounding up to a nearest power of 2
  spice: fix invalid memory access to vga.vram
  qxl: document minimal video memory for new modes

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