GitLab

Add files-contrib/webos-*.mcf files for webOS OSE fork with Yocto 2.7 Warrior, 3.0 Zeus, and 3.1 Dunfell

* Set upstream layer pins to HEADs as of 2020-01-16.

* Start tagging The branches in meta-webosose every time they are
  rebased on newer webOS OSE build or when adding more changes for
  compatibility with newer upstream layers. This way the build of
  DISTRO = webos should always work and you would be able to go back to
  older revision as well (without needing to find some compatible
  meta-webosose revision on your own).

* Fetch meta-ros-webos from shr-project because ros/meta-ros-webos
  doesn't have branches for these OpenEmbedded release series.

* Also add meta-webos-backports-3.1 that's been added to meta-webosose.
Signed-off-by: Martin Jansa <martin.jansa@gmail.com>