Tag editor: "short cuts" for tag combinations

[Bernhard Hiller <bhil@…>]

Many items receive combinations of tags, e.g. unpaved minor roads receive highway=unclassified and surface=unpaved, Buddhist temples receive amenity=place_of_worship and religion=buddhist, mosques amenity=place_of_worship and religion=muslim, bridges receive bridge=yes and layer=1 etc.
Now I wish to enter a shortcut into the tag editor which then gets expanded to the underlying tags.
Example: I enter extra=br1 in the tag editor, after OK both bridge=yes and layer=1 are added to the tags of the way.
Since the combinations are quite individually used, a dialog for defining them is also required. There I would enter "br1" as the value of the "extra" tag, and say that it means bridge=yes and layer=1.