Moved fields to server

Starting to understand how to hook up client and server. Now the JSON list
of search fields comes from a GET request to the server. Still a dummy
list though.
Added configuration stuff in a YAML file.
Full screen layout

Still playing with flexbox - trying ways to get the app to be full screen.
This works for now.
Connecting to the SW web service

The back-end should be able to send requests to the Semantic web-service
of choice. This sends a sample query and parses the results.