it was becoming too complex; now we are running multiple containers
from the same image. Coordination between those processes is not needed
(db is where it happens), so it should work.
waiting psql to be alive is a duty moved to a wrapper script "wait-db"
a syslog image will log everything it receives on stdout; so every
service that has a hard time logging can just send everything to it.
apache/ttrss configured to do it.
this is a big change: OpenRC introduced to tt-rss container.
However, this also means that environment variables set in
docker-compose.yml are not passed to apache.
also, state dirs are moved to /var/cache/ and /var/lock/, thus avoiding
their unneeded "copy" to host.
ICONS_DIR is still pointing to documentroot, so this is not yet
complete.
