Add TrajOpt launch files to panda_moveit_config (#29)

* added new files for emptyplan

* edited demo.launch to accept planner arg

* Added emptyplan_planning.yaml so it can be used for new planners. It is an empty file.
Added rosparam in emptyplan_planning_pipeline.launch.xml to load its yaml file

* from empty to trajopt

* modified some comment

* renamed and edited the context of files from empty to trajopt

* removed  move_group_trajop.launch, we do not need this file

* applied Dave's comments

* restored setup_assistant

* added trajopt params in yaml file
removed extra planner arg in demo.launch

* addressed the comments

* corrected pipeline in move_group