[wip/morse-ros] Upgrade to 1.4

Changes since 1.3:
==================

- Some ROS 'housekeeping' has been performed in this release, including
  removing the need for rospkg (easier installation!), removing ROS interface
  with the non-standard (and unused?) JointPositions message and removing
  references roslib.load_manifest(), a memory of rosbuild-era.