wayland/egl: rework resizing (again)

Moves a good chunk of the resizing code to wayland_common.c. This makes it
possible to share it with future video drivers.

It doesn't resizit it immediatly, it calcutlates the new position and size and
then shedules a resizing event. This removes the ugly callback and void pointer
from the wayland data structure.
wayland: remove shm listener for the backend

The obtained information from the shm listener isn't used by anything and is
also wrong now in wayland git master branch because of new shm formats which
need a different way of saving the supported formats.
wayland: shm based software rendering

Prototype

No resizing
No OSD
No subtitles
usw.
wayland: update shm backend

Copy resize function from gl_wayland.c
Move the tempfile stuff from wayland_common to vo_wayland
Add osd drawing

Resizing is still buggy
wayland: fix shm resizing for good
wayland: update shm backend #2
wayland: update shm backen no. 3
wayland/shm: logging changes
wayland/shm: use the right rgb565 formats
wayland/shm: use a non default format first

This makes the playback almost 3 times as fast as with the default format.
wayland/shm: add option to use the defaul-format