The start of some refactoring.

Use typed view-models for data source collections instead of ad-hoc JSON +
komapping.

This is not done or at all working yet.
Fix jshint warnings.
Merge remote-tracking branch 'origin/master' into refactor
Merge remote-tracking branch 'origin/master' into refactor
Merge remote-tracking branch 'origin/master' into refactor
Remove data source username/password feature.

We're not using it anymore and it never quite worked right anyway.
Merge remote-tracking branch 'origin/removeUsernamePassword' into refactor
Update Cesium.
Merge branch 'removeUsernamePassword' into refactor
Update Cesium.
Remove Cesium WMS picking code.

It's built into Cesium.
Update Cesium.
Merge remote-tracking branch 'origin/master' into refactor

Conflicts:
	third_party/cesium
Ongoing refactoring.
Merge remote-tracking branch 'origin/master' into refactor
Merge remote-tracking branch 'origin/jshint' into refactor
Working toward creating view-models from JSON.
Improvements to GeoDataItemViewModels.
Export CzmlDataItemViewModel.
Improve compatibility with data.gov.au's CKAN.

Also fix click-on-title-to-zoom for all data sources.