Scale Improvements B

[gpaar]

1. it shall be possible to define the two colors for each scalebar and also the length annotation
2. A scalebar shall receive an optional name. This must not replace but only be attached to the length that should always be bound to it
3. Scale bars as defined in earlier scene formats shall be still supported for read
4. The surface that was used to define the pivot point of the scale bar shall be recorded in meta data
5. It shall be possible to take the default values of scale bars from a template scale bar that exists in the scene
6. It shall be possible to define a maximum distance from which the scale bar shall be visible
7. The re-positioning of a scale bar shall be possible, e.g. by dynamically dragging around on the surface (low priority)
8. Transfer parameters from one scale bar to others (similar to a format painting tool) (low priority)
9. Render shadows of scale bars (low priority)