ui/sdl2 : initial port to SDL 2.0 (v2.0)

ui/sdl2 : initial port to SDL 2.0 (v2.0)

I've ported the SDL1.2 code over, and rewritten it to use the SDL2 interface.

The biggest changes were in the input handling, where SDL2 has done a major
overhaul, and I've had to include a generated translation file to get from
SDL2 codes back to qemu compatible ones. I'm still not sure how the keyboard
layout code works in qemu, so there may be further work if someone can point
me a test case that works with SDL1.2 and doesn't with SDL2.

Some SDL env vars we used to set are no longer used by SDL2,
Windows, OSX support is untested,

I don't think we can link to SDL1.2 and SDL2 at the same time, so I felt
using --with-sdlabi=2.0 to select the new code should be fine, like how
gtk does it.

v1.1: fix keys in text console
v1.2: fix shutdown, cleanups a bit of code, support ARGB cursor

v2.0: merge the SDL multihead patch into this, g_new the number of consoles
needed, wrap DCL inside per-console structure.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Fixes & improvements by kraxel:
 * baum build fix
 * remove text console logic
 * adapt to new input core
 * codestyle fixups

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>