Cleanup of gazebo plugins (#46)

* Upgraded plugins for gazebo 7
* Fixed documentation on sensors

simulation/frc_gazebo_plugins/servo/src/servo.cpp

@@ -40,8 +40,8 @@ void Servo::Load(physics::ModelPtr model, sdf::ElementPtr sdf) {
     torque = 5;
   }
 
-  gzmsg << "initializing awesome servo: " << topic
-        << " joint=" << joint->GetName() << " torque=" << torque << std::endl;
+  gzmsg << "initializing servo: " << topic << " joint=" << joint->GetName()
+        << " torque=" << torque << std::endl;
 
   // Connect to Gazebo transport for messaging
   std::string scoped_name =

simulation/frc_gazebo_plugins/servo/src/servo.h

@@ -23,9 +23,10 @@ using namespace gazebo;
  * To add a servo to your robot, add the following XML to your robot
  * model:
  *
- *     <plugin name="my_servo" filename="libgz_servo.so">
+ *     <plugin name="my_servo" filename="libservo.so">
  *       <joint>Joint Name</joint>
  *       <topic>/gzebo/frc/simulator/pwm/1</topic>
+ *       <zero_position>0</zero_position>
  *     </plugin>
  *
  * - `link`: Name of the link the servo is attached to.