[Potlatch-dev] Introducing Magic Roundabout tool

[Steve Bennett]

I'm quite proud of this one.
----
Introducing the amazing Magic Roundabout tool. This tool creates a
roundabout from scratch. To use it, start drawing a way from the node
that will be at the centre of your roundabout. The length of the way
you're drawing determines the radius of the roundabout. Press 'M'.
Bam! In one hit, it:
1) Creates a circular way of the appropriate size and location, with
an appropriate (?) number of nodes.
2) Creates junctions wherever it hits any other roads
3) Determines the most appropriate highway=* tag (the "highest" of any
of the roads that it touches.
4) Sets those tags, plus junction=roundabout
5) Splits any ways that ran from the central node across the roundabout
6) Removes the interior half of those ways.

What it doesn't do:
1) Have a particularly newbie-friendly interface
2) Do anti-clockwise roundabouts
3) Do composite undo.
4) Handle any special cases. (I haven't really looked. It's 3am. The
undo stuff confused me greatly.)
----
http://trac.openstreetmap.org/changeset/25413

Oh, it also doesn't do relations. Or any bring across any other tags,
like surface=*, or ref=*.

Comments/suggestions welcome.

Steve