recorder: show maps for tracks with late-GPS

[bobrippling]

Previously if we didn't have GPS in the small snapshot we fetch:

BangleApps/apps/recorder/interface.html

Lines 720 to 724 in 0bfa101

	var tries = 100;
	var l = data;
	while (l && l.split(",")[lIdx]==="" && tries--)
	l = f.readLine();
	if (l) data = l;

then we wouldn't create the map element:

BangleApps/apps/recorder/interface.html

Lines 834 to 838 in 0bfa101

	${trackData.Latitude ? `
	<div id="map-${track.number}" class="leaflet-map"></div>
	<div class="track-stats">
	<span id="stats-${track.number}">Loading...</span>
	</div>` : ''}

We now create the map element and populate it with the track coords, or if no coords are found in the entire track, we hide it.

• Best to look at the diff ignoring the indent changes.
• Tested with:
  • A normal GPS file
  • A late-GPS file
  • An empty GPS file
• Deployed at my gh-pages

[bobrippling]

No problems with testing - merging