Merge remote-tracking branch 'remotes/kraxel/tags/ui-20180125-pull-request' into...

Merge remote-tracking branch 'remotes/kraxel/tags/ui-20180125-pull-request' into staging

ui: convert to keycodedb, fix sign extension
sdl: cleanups, deprecate sdl 1.2

# gpg: Signature made Thu 25 Jan 2018 14:31:47 GMT
# 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/ui-20180125-pull-request:
  sdl: reorganize -no-frame support
  sdl: use ctrl-alt-g as grab hotkey
  ui: deprecate use of SDL 1.2 in favour of 2.0 series
  ui: ignore hardware keycode 255 on win32
  ui: add fix for GTK Pause key handling on Win32
  ui: convert GTK and SDL1 frontends to keycodemapdb
  ui: convert the SDL2 frontend to keycodemapdb
  ui: avoid sign extension using client width/height

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