Copyright 2013 Bruce Ide

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

This program just dumps a GPX file as generated by mytracks to a KML file.
Currently it just dumps the GPX file as one big extruded linestring. I
include a couple of test GPX files to experiment on. It's mostly intended
as a starting-off point to a larger project.

You'll need several of my other libraries (coordinates, time, cppxml,
cppunit_contrib, data) to build this program. Make a $HOME/sandbox directory
and check them all out into directories under that one, and the makefile
should work OK. Requires a gcc compiler capable of c++11 (4.7.2 or later.)