Added dependency on visualization_msgs to make same as file in orig/
Updates to orig and work copies of perception lesson source file.
Deleted broadcaster, added a few more optional filters.
Reorganized optional code sections towards end.
Added code for optional filters in source file. Needed to add dependency to tf_conversions in CMakeLists and package.
Minor change to ref source file (format comment)
Minor changes - commented out lines with cloud names which do not exist yet.
Merge pull request #34 from gomezc/perception_lesson_updates

Perception lesson updates