Added a nicer JSON, also started adding edges.
Merge remote-tracking branch 'origin/8-endpoint-reference' into messaging-ui
Removed the ZeroMeasurable with a unit

The new Measure.zero method does neet a unit. This is because sometimes
the zero point of two units are not the same (e.g. for Kelvin, Celcius and
Fahrenheit). It therefor makes no sense to create a 'zero temperature'.
Merge remote-tracking branch 'origin/development' into messaging-ui
Merge remote-tracking branch 'origin/messaging-ui' into development
Merge remote-tracking branch 'origin/fix-zero-measurable' into development