Added the ability to read scaling from resource files. This is specifically important for reading scaling factors from Collada files to maintain consistency with the way Gazebo interprets them.
Adapted RobotModels to use the unit scaling factor for compatibility with Gazebo's interpretation of Collada files
Adapted mesh markers to use the unit scaling factor for compatibility with Gazebo's interpretation of Collada files
Merge branch 'collada_loader_units_fix' of github.com:jon-weisz/rviz into groovy-devel
mesh loader: removed stray warnings