GA Gazetteer Search

Hi Team!

I'm currently tasked with building additional features required by GA for national map. I've expanded the search widget to include a way for users to search GA's place name Gazetteer as requested.

#### Main changes
1. Introduction of jQuery UI
2. Fixes for z-index to allow more levels between overlay and map.
3. Knockout binding for jQuery UI Autocomplete

I've noticed none of the more common UI frameworks are being used in this project, so please let me know if this introduction of a dependency on jQuery UI is a problem.

I've tried to follow conventions I've found in the project as much I could whilst building this feature, but would be very appreciative of any feedback.

Cheers!