remove redundant/incorrect code.

there is no need for an `initialized_` flag, because the controller manager
will call `starting` to indicate the first iteration of a control cycle.

The controller already does the correct thing in `starting`. If instead the
code in `starting` were removed, and the `initialized_` flag kept, then this
position controller would (incorrectly) jump to the previous set point if it is
stopped and started (for example, if you hit and release the run-stop), since
the `initialized_` flag was only being cleared in the constructor.

Author: goretkin

robot_mechanism_controllers/include/robot_mechanism_controllers/joint_position_controller.h

@@ -113,7 +113,6 @@ class JointPositionController : public pr2_controller_interface::Controller
 
 private:
   int loop_count_;
-  bool initialized_;
   pr2_mechanism_model::RobotState *robot_;              /**< Pointer to robot structure. */
   control_toolbox::Pid pid_controller_;       /**< Internal PID controller. */
   ros::Time last_time_;                          /**< Last time stamp of update. */

robot_mechanism_controllers/src/joint_position_controller.cpp

@@ -44,7 +44,7 @@ namespace controller {
 
 JointPositionController::JointPositionController()
 : joint_state_(NULL), command_(0),
-  loop_count_(0),  initialized_(false), robot_(NULL), last_time_(0)
+  loop_count_(0), robot_(NULL), last_time_(0)
 {
 }
 
@@ -141,12 +141,6 @@ void JointPositionController::update()
   assert(joint_state_->joint_);
   dt_= time - last_time_;
 
-  if (!initialized_)
-  {
-    initialized_ = true;
-    command_ = joint_state_->position_;
-  }
-
   if(joint_state_->joint_->type == urdf::Joint::REVOLUTE)
   {
     angles::shortest_angular_distance_with_limits(