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

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

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

Added option to specify config file
Moved docker build out of ox-installer
Fixed broken docker build
Updated readme

Guard not working as expected