[arm_ctrl] Improved handling of states and substates for returning error conditions.
[arm_ctrl] Improved handling of states and substates for returning error conditions.

ScazLab/human_robot_collaboration,ScazLab/baxter_collaboration,ScazLab/human_robot_collaboration,ScazLab/human_robot_collaboration,ScazLab/baxter_collaboration,ScazLab/human_robot_collaboration,ScazLab/baxter_collaboration,ScazLab/baxter_collaboration