manpage: use Lua for Lua example
build: add SONAME to libmpv.so
video: fix --no-aspect

This also affects the --aspect option and the "aspect" property.
manpage: document --aspect special values

Use of these is "discouraged", but they're there to select these special
cases with the "aspect" property. They really should use some sort of
choice option type, but since it would be some work to make these work
with float values, the simple and dumb alternative was picked.
manpage: fix Lua script shutdown description again

It was split at the wrong sentence.

Also, sneak in a reference to mp.suspend.
wayland/shm: prevent the window from flying away

With the new xdg_shell the problem will be no gone by itself.
wayland/shm: rewrite buffer handling

I was unhappy with the old way of handling buffers, especially resizing. But my
original plan to use wl_shm_pool_resize wasn't as good as I initially thought.
I might get back to it.

With the new buffer pools it now possible to select triple buffering. Also the
buffer pools are also needed for the upcoming subsurfaces for osd and subtitles.

I hope this change was worth it.
man: update wayland options
Merge branch 'master' of https://github.com/mpv-player/mpv into bpc