Add CoP calculation

- Add sum, divide, subtract operations
- Change datasets API
- Simplify dataset calculation
Merge pull request #61 from MastodonC/feature/cop

Feature/cop
Fix lower and upper bounds for the sensor.
Merge pull request #62 from MastodonC/feature/fix-bounds

Fix lower and upper bounds for the sensor.
Fixed display of property id in table.
Merge pull request #63 from MastodonC/feature/property-details

Fixed display of property id in table.
Use dirty dates for datasets.
Initialise dirty dates for datasets and other fixes
Fix typo in render-item(s).
Add multiply operation.
Merge pull request #66 from MastodonC/feature/calculated-fields

Feature/calculated fields
html 5 and ecmascript5 shim/sham/shivs

So that we can be compatible with older IE browsers.
Bootstrap support for older browsers.
Removed console printlns.

To avoid IE 8 problems.
Shims, shams and shivs for IE8.

All the extra things you need so things don't blow up in broken old
browsers.
Don't execute dimple.js code in IE8 or earlier.

IE8 and dimple.js don't get on at all. There *may* be some alternatives
for d3.

This means that older browsers currently don't have any charts.
We're getting shims from the cdn instead.
Missed a shim.
Merge pull request #68 from MastodonC/feature/ie8-fix

html 5 and ecmascript5 shim/sham/shivs
Implement template downloads.