* no more usage of slow vufind-php image for various containers
* use stock docker library images where possible for faster startup
* build custom images for php and composer only to include xdebug and required extensions
* provide and leverage custom entrypoint shell scripts for most containers
* inject environment variables defined in docker-env.*.yml files within entrypoints
* place environment variables defaults in in docker-env.0.finc.yml
* place composer and npm caches in git-ignored subdirectories of project root directory
* gracefully terminate all container processes (especially grunt and mail) for faster shutdown
* let versions of php and mariadb equal those in current live systems
* let container-written files have uid/gid of project root directory by default
* forward exposed container ports to non-standard ports on host system
* allow to override uid/gid of written files as well as host ports via environment variables

* specify exact autoconfig version to install
* avoid recursive call to chown in env entrypoint
* drop unnecessary argument when calling grunt

* report all errors (including notices, deprecation messages etc.)