Optimised map data

Optimised coords to 1 dp ( and 5% simplification) using mapshaper.org
Optimised json to remove scotland

Altered code reference to match old ONS codes for Northumberland and
Gateshesad
Map example using area names in data source

Note the the ONS id is better as there are inconsistencies in names
Merge pull request #41 from mcoulthurst/master

optimised map oultine data