Added new dashboard item with alternative CO2 calculation taking only local emissions into account (not for imported electricity)
Add local CO2 reduction dashboard record

* Added the Constraint record to show the local CO2 reduction item.
* Tweaked some CoffeeScript to reduce duplication.
* Updated the I18n JS.
Create _local_co2_reduction.html.haml
Merge pull request #1838 from quintel/new_co2_dashboard_item

New co2 dashboard item