Tests and implements feature count stats
creates models: country_statistics, regional_statistics and regions
Adds Relationships between countries, regions and stats
adds global satistics: percentage_cover_pas and pas_with_iucn_categories
adds protected areas count by description
counts the number of countries with pa's
adds pas by country stat and iso column to regions
Adds classified by IUCN/countries pa count
Adds designations count per country
Adds count pas by designation for each country
refactors stats
fixes region typo
Merge branch 'master' into stats

Conflicts:
	db/structure.sql
Merge pull request #10 from unepwcmc/stats

Stats Calculator