Save Metadata to Objects to ease the creation of the control description

[dg0yt]

Somebody reported on Sourceforge [tickets:#325]:

It would be usefull to save the Dimensions of holes or openings in the Object. When you use an Object as a control, the dimensions could be loaded automatically in the control description.

[dg0yt]

• labels: --> Tags
• status: new --> open
• assigned_to: Kai Pastor

[dg0yt]

This a potential application of object tagging #178 and so already part of 0.6.0.

What we will need in the long run is a standard how to name tags. This standards must take into account that one might want to track the source or interpretation of a tag, such as OpenStreetMap, DXF, control description. I could imagine to use a small prefix, e.g. osm:road, dxf:name, cd:width.