Added Subscriber to sensing node and parameter to a launch file
The "update_topic_name" parameter has been added to the system_full.launch file. It can be used to specify the topic each sensing node should subscribe to in order to get the other robot's position.
The "robot_name" arguments have been added to the system_full.launch file to specify the robots' names.
Changed name of "update_topic" parameter to "other_robot_topic"