Add some more Hydro packages.
Minor updates.
Add rqt and its dependencies.
Add robot_state_publisher and its dependencies.
Add more hydro packages (pcl...).
Add more rqt plugins.
Add navigation tutorials and their dependencies.
Add ros_comm and ros_control.
Add some gazebo ROS Hydro stacks.
Add moveit packages for hydro.
Fix some Ogre 1.8 linker errors (conflicts with Ogre 1.9).
Add PR2 support for hydro (pr2_robot stack and its dependencies).
Add moveit_pr2 and its dependencies.
Update catkin_pkg and catkin.
Add Git as a dependency.
Add more hydro tutorials.
Add ROS metapackages/variants.

See: http://www.ros.org/reps/rep-0131.html#variants
PCL fixes + separate build/run dependencies.
Fix roslib.
Update python2-empy + fix some yaml-cpp dependencies.