WayEditor: resurrect deleted nodes

If there are orphaned nodes scheduled for deletion in finalizeEdit(), these
nodes can be resurrected as originals for newly added nodes. In cases like
RUIAN building retracing, resurrection reduces the number of edit operations
and overall growth of OSM database.

Resurrection is limited by a maximal distance between the old and the new node,
resurrected nodes are paired with new nodes according to their minimal relative
distance.
Merge branch 'wayeditor-devel' into development