All executable files present in /entrypoint-tasks/pre-setup/ and
/entrypoint-tasks/post-setup/ are run at the beginning
or at the end, respectively, of the actual entrypoint-script.
Each of the executed files receive the CMD given to the container as their
arguments. This allows e.g. to change a plugin's config, or install a
technical requirement of a plugin that is to be installed.
This feature is not implemented in the images for Roundcube v1.5, since
they are not well maintained and will be dropped soon, anyways.
Adds an additional stage to the Dockerfile to create images with default user www-data.
The apache webserver listens on unprivileged port 8000 instead of 80.
Publish all variants with an additional tag ending in `-nonroot` for distinction.
Refs: #306
