WIP
Renamed Module_DEMWithOverlays to RectangularBoxViewerModel
Refactored the RectangularBoxViewer functionality into its own library: RBV. This makes it easier to separate the functionality between VMANIP and the EarthServerClient framework. The short/midterm plan is to remove the EarthServerClient framework from the RectangularBoxViewer repository and add it as a dependency.

This is the first step to close #1.
Fix for bounding box parameter
Fix for resetting the scene if no terrain is created yet in the model
Removed old code
Moved distributable files from js/ to dist/ and adapted grunt setup
Removed old dev script