Add first rough version of doctor search, doctors will be returned sorted by distance from reference point

	modified:   .gitignore
	modified:   app/models/database_adapter.rb
	new file:   app/models/doctor_locator.rb
	modified:   app/models/information_providers/database_info_provider.rb
Fix problem with nil values for lat/long, distance now calculated with spherical trigonometry and returned in kilometers

Geocoder gem installed, needs 'bunle install'!

	modified:   Gemfile
	modified:   Gemfile.lock
	modified:   app/models/database_adapter.rb
	modified:   app/models/doctor_locator.rb
Merge branch 'development' of github.com:pse4/orange-proton into development