The goal here is that the code that draws the targets should know better
what parts of the lines/vertices are targetable, rather than just
relying on CSS to ignore the pointer events on the whole line.
e.g. when drawing a line, it's ok for it to loop back and connect
to itself, just not on a segment or vertex adjacent to the active
node.
(closes#3663)
* Add Nuclear Explosion Site and Military Office presets
* Add Bunker Type field
* Improve styling rules for preset icons
* Improve search terms for all military presets
* Nest military presets under `landuse=military`
* Add ref, iata, icao fields to Military Airfield
* Don't set area pattern fills on buildings
This includes some renames for clarity.. "surface" -> "selection"
to make it clearer that rendering functions take a selection, and
don't necessarily render to the literal `#surface` node anymore.
Bryan Housel