A few more changes to planner GUI before removing...

< feeling sheepish >
Splits PathPlannerTest into two programs, one for solving paths, and one for interpolating bezier commands.
It doesn't semantically make a difference, but if you don't want to have to use pointer notation, you could do this:

`GLWayPoint& a = planner_gui_.GetWaypoint(0)->m_Waypoint;`

Then in the following lines you could just say `a.GetPose4x4_po()`. Again, no difference in behavior (probably gets compiled to the exact same thing), just want you to know your options.