Update setpoint_velocity to simple twist for compatibility with ROS n…

[khancyr]

…av stack

Current setpoint_velocity require twistStamped but all ROS navigation stack and what is ising move_base is using simple Twist (http://wiki.ros.org/move_base?distro=kinetic ). Using simple twist will allow direct mapping from navigation to setpoint_velocity and use ROS controllers

[vooon]

I'm not sure that i want to break ROS API. Maybe better add additional subscriber?

[khancyr]

@vooon Ok I will rework that tomorrow to just add the twist listener . I submit this before talking to you because I didn't find an example in ROS using cmd_vel with twistStamped, But if it was done like that before, just adding a subcriber will preserve current compatibiliy and add more on ROS side!

[vooon]

Old version of plugins has subscriber type switch parameter, but i removed it because of error prone.

[khancyr]

@vooon ok, rebase and twist listener added. It is working as intend with ROS nav stack see https://www.youtube.com/watch?v=kYMzVeW-0-E&index=5&list=PL6sCNLbHuYxaLtItzADD5zHxixUtQPSvk as example (I know slam is failing but vel order are well send !)

[vooon]

Merged. Thank you!