Provide TF buffer to PlanningSceneMonitor

[rhaschke]

#273 introduced a PlanningSceneMonitor in the motion_planning_api_tutorial. However, as no TF buffer was provided to the PSM, it isn't able to resolve TF frames, which caused a multitude of issues after having switched to a floating virtual joint for the Panda robot:

• Regression on the current kinetic-devel panda_moveit_config#33
• No joint state information if virtual joint is set to floating panda_moveit_config#38
• motion_planning_api Tutorial Hangs "Waiting for complete state from topic " #312
• Motion Planning API tutorial stuck in loop waiting on haveCompleteState. Related to #1399 moveit#1414

This PR fixes these issues by providing the required TF buffer.
However, thinking more about it, I suggest completely removing the PSM. I will file an appropriate PR.

[rhaschke]

Closing in favor of #387.