Default Building tag is not smart, should default to existing value

[mackerski]

The "Building" option in the dialogue always defaults to "yes", even if the selected way that is to be split already carries, say, building=house. The current tag should always be offered as the default.

[moltonel]

Or if there isn't a building tag on the way yet, default to whichever value was used last, a bit like the housenumber tagging tool does.

[skyper]

As your are loosing information if an explicit value does already exist this is a bug

[skyper]

This is fixed.

[Don-vip]

Fixed in [o30611:30615].