General Enhancements and Bug fixes

This release fixes a few bugs and adds a couple of new features/ enhancements

1. New: Ability to search/filter on localities and local_admin layers &layers=locality
2. New: API now uses the optimized bbox query which cuts down the response times by one third.
3. Bug Fix: Filtering by layer is now working on all endpoints (/suggest, /search, /reverse)
4. Bug Fix: No Internal server errors when you pass in lat=0 and lon=0