0.7.3 - Piz Albula

• Notices page with licenses information
• circles with title or description, show popup on click #135
• default snapshot permission NOT_LISTED #68
• Added git tag & commit version to footers of frontend and backend
• django backend footer, color and html-structure change
• attribution on Map also in Snapshot View
• attribution through mapbox js instead of html template
• openstreetmap attribution on map in new municipality mode
• adds wms support, pass simply all wms layer.parameters to leaflet