[aur-general] docker v. docker

[Jerome Leclanche]

extra/docker is currently a very old system tray app for openbox2,
kde3 and gnome2. It hasn't been updated in a very, very long time.

docker (https://www.docker.io/) on the other hand, is a widely used
and current container solution. As of 0.7, it's now available on all
distributions (previously was only available on ubuntu).

There will be a naming conflict between the two very soon. I would be
in favour of renaming extra/docker preemptively since it hasn't been
updated in a decade.

J. Leclanche