Due to some different behavior of the distributions that may be used for docker setups it was necessary to implement some checks for supervisord and its configurations

mysql 5.6 is not supported on buster

Since documents is still not merged / installable i removed it from the default setup. Feel free to try it later on manually by adding the repos.

Missed some distribution check

Configurable via config/config (type and version)

Re-added retry logic from qa/installer to prevent failed setups due to updated buildservice repositories while installer is preparing

in preperation for mariadb, now with configurable mysql version support (works on Debian 9/10, CentOS6/7)

SSL now works on CentOS/RHEL

Moved guard init, fixed missing update-themes
Moved docker into its own directory, added singlenode and cluster environment (only singlneode works rn, cluster wip)

All other distributions ship some java 8 packages

This reverts commit da217a4b.

Moved documents init

Warning: youl have to use the specific feature branches for the gdpr feature!

Moved setup steps for documents and guard to its own scripts
Fixed order of component installation