weston: change to use meson build system

weston: change to use meson build system

The changes include:
- Drop all autotools related patches.
- Move weston-launch setuid-install to do_install task since it's not
  supported yet by meson build.
- Drop cairo-glesv2 package config, it's not supported by meson build,
  the recommended value is hard-coded to cairo-image for now in weston
  source.
- Introduce remoting package config, to give this option a explicit
  value, or else the build would run into gstreamer missing error since
  it defaults to be true but gstreamer is not in depends list.
- Default to headless backend if neither x11 nor wayland is in
  DISTRO_FEATURES.

To be noticed, the packages built from meson would not be identical
with those built from autotools, for instance, libz dependency has been
dropped from meson build, and systemd-notify is always built in meson
when systemd packageconfig is enabled, which in autotools, it's
optional, and so on, it's not easy to list all the differences, but
you could get them by comparing the pkgdata directories built by meson
and autotools.

Signed-off-by: Stefan Agner <stefan.agner@toradex.com>
Signed-off-by: Ming Liu <ming.liu@toradex.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>