Remove code for EGL_WL_request_client_buffer_format.

This appears to have no supported use in the open source or modern world, so
drop the dead code.

Change-Id: Ic08a6bf2c844da567e8f76cec7201ee31ded5b81
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Jan Arne Petersen <jan.petersen@kdab.com>
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
Use new EGL_WAYLAND_Y_INVERTED_WL attribute to query Y inversion of a buffer.

Change-Id: I1532ad432cf1a6a1b1ba9c960a8b575f801b8331
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
Compositor: Ping/Pong API

Provide a way for the compositor to ping (and receive a pong) from
surface clients.

Change-Id: Iab594f0357fdfc25fe01ca0b8b9f527149718b44
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
Reviewed-by: Jan Arne Petersen <jan.petersen@kdab.com>