The GPX schema requires waypoints to come before the track.
Waypoints are not currently used in TCX export, so there are no
changes there.
In KML files, both tracks and waypoints are "Placemark"s, so it
doesn't matter what order they come in there.
This does change the order they appear in CSV files, which could
potentially invalidate some assumptions made in downstream tools.
Addresses issue #299 and ensures Latitude and Longitude are formatted
correctly as well.
Also orders the elements in the waypoint correctly according to the
schema: <ele> and <time> need to come before <name> and <desc>.