(task_handler_layer) Add on-off switch to IP nodes

[pkhrag]

@siddsax to control IP nodes from task handlers, we directly use system(rosrun ...). But we want to run all the nodes (all ip nodes and task handlers) in parallel so we need to add a switch that will turn on and off the ip nodes. It has already been done in task buoy. The server publishes on a topic (boolean data type) which is subscribed by the ip node that changes a global boolean variable which is checked in a if condition in the main while loop. If that boolean is then only the whole processing of images starts. So you need to add similar check in all the other IP nodes including line detection and line following node.

[ShikherVerma]

closed by #131