Stats pages

This pull request adds the Stats pages:

Global:
/stats/global

Regional
/stats/regional/[:iso]

Country
/stats/country/[:iso]

Adds 3 controllers (one for each stat type) in the /app/controllers/stats foder.

It also creates an integration test and controllers tests for the features above.

Still work to do on CSS and and the views may be refactored.

Geospatial stats are not available so they are commented in the controllers and not present in the views
At the moment these tests just assert that the page rendered is equal to the page rendered. Perhaps you could build up some basic Country, etc. models and assert that the numerically correct stats are being shown?