remove hardcoded parameter from esri geocoder service

move `maxLocations` hardcoded parameter into searchController
use `$interpolate` to build SQL strings
leaflet accessibility enhancements

- add `@for` for labels in map controls
- improve zoom control html text
remove console.log
calculate map bounds when searching by location

- zoom in on search area
- geocode of search available to searchController
order by distance when searching by location

- ckan API orders by distance from location
- search results ordered by distance
- map focuses on search area
Merge pull request #18 from qld-gov-au/search

Search
Merge pull request #19 from qld-gov-au/MVPv1

add location searching