Merge pull request #179 from davetcoleman/get_subgroups_helper

Get subgroups helper
adding angles dependency
Merge pull request #190 from ros-planning/fix_angles_indigo

adding angles dependency
Documentation and made printTransform() public
Change PlanningScene constructor to RobotModelConstPtr
Added default values for iostream in print statements
New robot state to (file) stream conversion functions, documentation improvements
Getter for all tips (links) of every end effector in a joint model group
Line too long formatting