Web-based configuration

[troeger]

Setting all neccessary options in the INI file becomes increasingly painful, pollutes the Terraform / Docker config files and complicates upgrades.

The INI file should be reduced to the absolute minimum that is neccessary to run the application. Everything else should be handled in a web-based configuration, which also supports the import / export of the complete config set. Given that, it would be easier to create a new demo installation without keeping a TFVARS file around.