Feature/show selected excerpt on map#17

Created by: wasabideveloper

Implementation of feature #17 (closed) and fix of inheritance problem in BoundingGeometry class. (Closes #17 (closed) ).

• run tests
• tested views by hand:
  • /orders/new [GET/POST]
  • /orders/{orderId}
  • /downloads/{uuid}

Reviewed by:

• @das-g
• @njordan-hsr

Is it ok to merge it into this release? The issue is assigned to milestone next https://github.com/geometalab/osmaxx/milestones/next.