added new example where locations are plotted on top of a world map
added new example where locations are plotted on top of a world map

burnpanck/chaco,ContinuumIO/chaco,tommy-u/chaco,burnpanck/chaco,tommy-u/chaco,ContinuumIO/chaco,ContinuumIO/chaco,ContinuumIO/chaco,tommy-u/chaco,burnpanck/chaco