Add statistics endpoint /api/waterpoints/stats

Returns number of waterpoints of a given status in a given district
Add statistics endpoint /api/waterpoints/stats_by_district

Return number of waterpoints of a given status for each district
Use Eve's send_response for custom endpoints

This returns the proper response format, add adds headers according
to Eve's configuration e.g. CORS.
Add a simple status endpoint
First set of working d3 plots to start the discussion
Add /dashboard route to serve dashboard view
Allow grouping stats endpoint data by any attribute

Also allow arbitrary restriction through query parameters.
Aggregate population in stats endpoint
Endpoint for unique values of arbitrary waterpoint fields
Stacked bar chart showing summary status now dynamic

Uses stats_by API endpoint.
Add angular view for dashboard mockup at /dashboard
Add DashboardCtrl getting waterpoint stats
Add selectors for region, district, ward to dashboard view
Restrict districts/wards by region/district if selected
Add class content to ng-view div
Allow restricting status, stats endpoints with query params
Update embedded map in dashboard view
Add dashboard link to main menu
Add NavCtrl to provide location path
Use location path to select active nav element