Add PosVel and PosVelAcc interfaces.
Merge pull request #181 from ipa-mdl/pos_vel_acc

Rebased  #148 (Added pos+vel and pos+vel+acc command interfaces)
controller_manager: spawner: adding shutdown timeout to prevent deadlocks
spawner: fixing shutdown message
spawner: changing language
Merge pull request #185 from pal-robotics/fwd-port-161

Indigo port of #161