Corrected effort thresholds and friction values for UR5 urdf.

Added joint limited urdf and associated moveit package.  The joint limited package is friendlier to the default KLD IK solution

Added ur5 moveit library.  The Kinematics used by the ur5 move it library is unreliable and should be replaced with the ur_kinematics

Reorganized meshes to include both collision and visual messhes (like other ROS-I robots).  Modified urdf xacro to include new models.  Removed extra robot pedestal link from urdf (urdfs should only include the robot itself).