Add support to wl_shm for RGB565 buffers

[Kristian Høgsberg]

On Thu, Jul 11, 2013 at 04:08:19PM +0200, Tomeu Vizoso wrote:
> This version allows renderers to advertise support for additional pixel
> formats for shm buffers via new API: wl_display_set_additional_shm_formats
> 
> Additionally, clients can hint when creating a window the preferred pixel
> format.

Hi Tomeu,

The series looks good, I just have a few comments in reply to the
patches.  Sorry for the long delay, the 1.2 release took priority for
a while, but I think we're ready to start the 1.3 cycle now.

Kristian