* update supercronic to the latest release
* update tagging for base
* fix version tag for core
* put versions for all containers into labels instead
* define vcf_ref once
* remove cache-from as caches will be invalidated early on because of passing the git ref early on
* do not rebuild when publishing
* do not rebuild when publishing
* reduce layers required for env assignment
* pull newer base images for kdav, scheduler and ssl if available
* alsp publish tag for ldap containers
* fix publishing of ssl container
* add scheduler container for gabsync
Adds a general scheduler container to trigger tasks within containers.
Also adds gabsync to zpush image
* make scheduler dynamic
execute each cron job once at startup to see if they would succeed
* remove services scripts from core container (now is part of the scheduler)
* add "CRONDELAY" for tasks that should not be executed at startup
* add documentation
* clear out crontab at startup
