Merge pull request #4 from DVAlhadeff/master

On-demand attribute loading.
Merge pull request #5 from DVAlhadeff/master

Map popups when clicking on (non base layer) features.
Merge pull request #6 from DVAlhadeff/master

Enhancement to show/hide data table. CSS/style updates pending.
Added temporary loading screen.
Merge pull request #7 from DVAlhadeff/Graphics

Added loading screen.
changes #1

highlight polygon, go back to full extent when click a new layer, move
the zoom previous/next button