Fix waypoint shapes

[Agustin Alba Chicar]

After integrating with new Manifold version, all the waypoints became an arrow. We should distinguish them and assign the correct shape depending on their nature.

[Agustin Alba Chicar]

https://bitbucket.org/JChoclin/rndf_gazebo_plugin/pull-requests/39/issue-72-temporal-change-in-algorithm-for/diff will take track of it.

[Javier Iván Choclin]

Added a method for getting the vertex type. Removed unused code. refs #70

→ <<cset 8a2b3f5178bf>>