Implement template downloads.
Add sorting to template output for stability.

The test data was already sorted, so jiggled it a little to ensure that
sorting really happens.
Merge pull request #67 from MastodonC/feature/csv-template-download

Feature/csv template download
Fixed postal address display.

Got rid of ,,, in the case of blank address fields.
WIP Fuller property details.
WIP Debug navigation events.
Fix fetching tag.
Most of the basic property fields.
WIP remove logging.
Better history driven project fetching.
Fixed programmes fetching.
Snappier properties fetching.
Improved slug.
Property Details.
Sensor flattening.
Removing unneeded channel.
WIP Flattened sensors.
Fixed update bugs wip
Defend against bad property details data.
WIP better handling of state transitions.