*Bug* on fake and simple controllers controllers

[rafaelrojasmiliani]

roslaunchcan fail when loading parameters for simple and fake controllers here and here respectively, the command does not substitute the arm_id variable because <arg name="arm_id" default="panda" /> is missing in the corresponding launch files.

[rhaschke]

These files are included from move_group.launch via trajectory_execution.launch.xml, both times using pass_all_args="true". Thus arm_id (and other args) are inherited from move_group.launch. You should not launch those files directly.