use current position when starting (forward_command) position_controllers; effort and velocity still use 0.0
Check that waypoint times are strictly increasing

A precondition for all trajectories executed by the
joint_trajectory_controller is that waypoints must have strictly
increasing reach times. This changeset validates the precondition and
rejects commands that don't satisfy it.
Add missing dependency to tests target
Merge pull request #135 from ipa-fxm/test_initial_value_position_controller

use current position when starting (forward_command) position_controllers
Merge pull request #145 from pal-robotics/check-waypoint-timing

Check waypoint timing