Serve all media from development server

Previously only served the /media/images folder
Vagrant: Use port 8000 on the host
Added Dockerfile and configuration
Changed app directory within Dockerfile
Use dj-static for serving /static and /media
Cleanup of requirements files
Dockerfile cleanup
Replaced HOSTNAME setting with ALLOWED_HOSTS

Comma-separated to allow multiple entries
Reorg of docker/local.py
Detect database configuration from Docker link
Detect Elasticsearch configuration from Docker link
Detect Redis configuration from Docker link
Put collected static files and media in volume

So they persist
Added dj and deploy commands

dj - Gets you to manage.py
deploy - Runs post deploy tasks (collectstatic, compress, migrate and update_index)
Added setting to allow use of PostGIS backend
Make uWSGI serve static/media files

Also pre compress and gzip all static files during build
Merge pull request #16 from kaedroho/docker

Docker support
Dockerfile no longer based on kaedroho/wagtail-base