We want to set a prefix when starting the ur_common.launch, so we add
the prefix argument and set the parameter for the driver.

Updated to catkin.  ur_driver's files were added to nested Python directory for including in other packages.

Added launch directory to bringup package.  Left the old launch files to be backwards compatable for now.  Updated driver with SwRI internal changes.  Changed driver to accept ip address to match ROS-Industrial standard.  IP addresses for industrial robots are typically fixed.  Hostnames are not typically used (this is what the driver expected)