Remodeling the emergency stop button into an rqt plugin.
First attempt. Limited functionality.
Missing connect function added to give some functionality to the button.
Complete restructuring.
Getting rid of ros_comm because it is not needed and complicates erverything.
Bug fixing:
forgot to start the ros:spin thread and had to add a ! for the colour change

The button is now a bit smaller to be able to use something else besides the button in rqt.
The colour is now only changed if there is real change in the value.
Added some comments and deleted rubbish from package.xml
start with assumption that motors are off in the beginning.
changed initial motor state assumption to motors are running.