Moved `MapButton` widget to `/map`.
Map Layers button wired to bootstrap popover. Closes #6.
fixed build
Added MapLayersPopup content.

Including reference layer toggles and base maps switches.
Closes #7.

Included some new Jasmine watchers that should probably end up in their own repo at some point.
Merge pull request #15 from agrc/map-layers-popup

Map layers popup