Note that 'base' is essentially 'base_link' but rotated by 180
degrees over the Z-axis. This is necessary as the visual and
collision geometries appear to also have their origins rotated
180 degrees wrt the real robot.

'tool0' is similar to 'ee_link', but with its orientation such
that it coincides with an all-zeros TCP setting on the UR
controller. Users are expected to attach their own TCP frames
to this frame, instead of updating it (see also [1]).

[1] http://wiki.ros.org/Industrial/Tutorials/WorkingWithRosIndustrialRobotSupportPackages#Standardised_links_.2BAC8_frames

https://github.com/ros-planning/moveit_core/issues/158

https://github.com/ros-planning/moveit_core/issues/158

base_link a dummy link to better support MoveIt.

Corrected effort thresholds and friction values for UR5 urdf.

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).