Calc datasets dev sketch,
Total kWh

Use the same function to update bounds and calc start/end when inserting measurements.
Create one synthetic sensor for total calculations.
Fill in the gaps when calculating difference series.
Custom add and min and max dates from all sensors in a dataset (used for padding).
Create additional sensor type for difference series.
Difference series stored in measurements table.
Difference series sensor becomes PULSE.
Remove references to difference_series table.
Merge pull request #33 from MastodonC/feature/datasets

Feature/datasets
Added friend dependency.
wip
Fixed paths in 404 handler.
wip.
It lives!
login works and there is a session! w00t!
Main app page.
Serves cljs from new resources directory.
API route function.
wip. Can pass config to handlers in routes.
Removed bidi from programmes resource.
Removed unnecessary handlers from programmes resource.
<------------------ Full Width ------------------>

On the main app page.
Programmes space & redundancy tidy up.
More programmes tidy up.
Added projects resource
Programmes tidying.