Converted ROS_DEBUG and ROS_WARN calls

Converted ROS_DEBUG and ROS_WARN calls to ROS_DEBUG_NAMED and ROS_WARN_NAMED calls with the namespace "pluginlib.ClassLoader"

This is useful when looking at DEBUG output from nodes such as MoveIt because it allows you to suppress large amounts of irrelevant debug information such as

```
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Creating ClassLoader, base = moveit_controller_manager::MoveItControllerManager, address = 0x3779b30
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Entering determineAvailableClasses()...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_pr2/pr2_moveit_plugins/pr2_moveit_sensor_manager_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = pr2_moveit_sensor_manager/Pr2MoveItSensorManager.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_pr2/pr2_moveit_plugins/pr2_moveit_controller_manager_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = pr2_moveit_controller_manager/Pr2MoveItControllerManager.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_pr2/pr2_moveit_plugins/pr2_moveit_kinematics_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = pr2_arm_kinematics/PR2ArmKinematicsPlugin.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/clam/src/clam_moveit_plugins/clam_moveit_controller_manager_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = clam_moveit_controller_manager/ClamMoveItControllerManager.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_ros/planning/planning_request_adapters_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/Empty.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/FixStartStateBounds.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/FixStartStatePathConstraints.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/FixWorkspaceBounds.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/FixStartStateCollision.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = default_planner_request_adapters/AddTimeParameterization.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_ros/planning/kdl_kinematics_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = kdl_kinematics_plugin/KDLKinematicsPlugin.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Processing xml file /home/dave/ros/moveit/src/moveit_planners/ompl/ros/ompl_interface_ros_plugin_description.xml...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: XML file specifies lookup name (i.e. magic name) = ompl_interface_ros/OMPLPlanner.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Exiting determineAvailableClasses()...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Finished constructring ClassLoader, base = moveit_controller_manager::MoveItControllerManager, address = 0x3779b30
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Attempting to create UNMANAGED instance for class clam_moveit_controller_manager/ClamMoveItControllerManager.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Class clam_moveit_controller_manager/ClamMoveItControllerManager maps to library libclam_moveit_controller_manager in classes_available_.
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Iterating through all possible paths where libclam_moveit_controller_manager could be located...
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Checking path /home/dave/ros/misc/devel/lib/libclam_moveit_controller_manager.so 
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Checking path /home/dave/ros/misc/devel/lib/libclam_moveit_controller_manager.so 
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Checking path /home/dave/ros/clam/devel/lib/libclam_moveit_controller_manager.so 
DEBUG ros.moveit_ros_planning.pluginlib.ClassLoader: Library libclam_moveit_controller_manager found at explicit path /home/dave/ros/clam/devel/lib/libclam_moveit_controller_manager.so.
```