Added units information to surface area. Renamed field to be more easy to understand: Room total Area for rooms and Property Total Area for the total area of the property.
Fix spelling
Isolated scope, so this directive could be used in other projects
Renamed nonMetric to imperial
Merge pull request #8 from monteiro/non-functional/frontend/noissue/addPropertyAreaUnits

Implements NOISSUE: Added units information to surface area
Sign-off: @mumia