Output GPX routes

[JarnoLeConte]

Instead of tracks <trk> also routes <rte> could be returned if the option {"gpx.rte": true} is provided. Evenmore you can specify to disable the <trk> or <wpt> output by setting {"gpx.trk": false, "gpx.wpt": false}.

Where MultiString, Polygon, MultiPolygon, and GeometryCollection will return a single track consisting of possibly multiple track segments, in the case of routes just multiple routes are returned due the lack of segments in that format.

Example:

togpx({
  type: "Feature",
  properties: {},
  geometry: {
    type: "GeometryCollection",
    geometries: [
      { "type": "MultiPoint",
        "coordinates": [ [31.0, 0.0], [32.0, 0.0] ]
      },
      { "type": "MultiLineString",
        "coordinates": [ [[101.0, 0.0], [102.0, 1.0]], [[103.0, 0.0], [104.0, 1.0]] ]
      }
    ]
  }
}, {"gpx.rte": true})

Output:

<gpx creator="togpx" version="1.1" xmlns="http://www.topografix.com/GPX/1/1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">

  <wpt lat="0" lon="31">
    <name/>
    <desc/>
  </wpt>

  <wpt lat="0" lon="32">
    <name/>
    <desc/>
  </wpt>

  <trk>
    <name/>
    <desc/>
    <trkseg>
      <trkpt lat="0" lon="101"/>
      <trkpt lat="1" lon="102"/>
    </trkseg>
    <trkseg>
      <trkpt lat="0" lon="103"/>
      <trkpt lat="1" lon="104"/>
    </trkseg>
  </trk>

  <rte>
    <name/>
    <desc/>
    <rtept lat="0" lon="101"/>
    <rtept lat="1" lon="102"/>
  </rte>

  <rte>
    <name/>
    <desc/>
    <rtept lat="0" lon="103"/>
    <rtept lat="1" lon="104"/>
  </rte>

</gpx>

[JarnoLeConte]

If you are planning to accept this PR, you can better look at #11. That PR is built on top of this one. In meantime lots has changed, so it's not worth spent a lot time to make this PR perfect, I guess.

Sorry, I haven't done PR's before. It's almost new to me.

[tyrasd]

I see. Let's close this one.