Changes towards the standard installation

I have modified the standard installation in the following way:

Based on dockerfile for django (from standard fermentrack)
Added ngnix and redis to django image
Modified startup script to set environment variables
Added supervisor to manage starting the needed processes
Volumes log, db and data can be mounted
Most functions in fermentrack should work, including GIT upgrades.
Serial connections will only work if docker is running on a linux host and the container is running in privliged mode.
Access rights on mounted volumes as well as database migrations are done before fermentrack starts at startup.
During startup you can also see what git repo is used as source, linux kernel, nginx and redis versions and when docker image was built.
The startup will automatically detect if the container is running in priviliged mode and set the capabilities accordingly.

The following are planned changes to be implemented