-Add model for sick robot day 2014 ring
Merge branch 'hydro-devel' of https://github.com/tu-darmstadt-ros-pkg/hector_gazebo into hydro-devel
-Add sick robot day 2014 related files
-Add sick robot day number panels
-Add collada files for sick robot day number panels
-Add sick robot number panel stl file for collision geom
-Change light for sick robot day 2014 world, add number panel example
hector_gazebo_worlds: updated world files to SDF 1.4 using gzsdf
Merge remote-tracking branch 'origin/indigo-devel' into hydro-devel