Links can be rendered with differents type of head : triangles, points or no head. It can be chosen in the settings menu.

New version of Render_alternate that does not need to store colors for each state. States aren't shaded

correct a bug causing states to use the default shader despite the shader associated to them by the map

Files vertexshader and fragment shader aren't needed anymore. They're replace by code strings. Some white-spaces cleanups.