Merge branch 'release-0.5.4' into develop
add old catkin compatibility
Merge pull request #231 from vrabaud/fix_em

add old catkin compatibility
force overridden methods to be at least classmethod
Merge pull request #232 from vrabaud/fix_bb

force overridden methods to be at least classmethod
fix potential crash for Fuerte on the farm
Merge pull request #234 from vrabaud/develop

fix potential crash for Fuerte on the farm
0.5.5
Merge branch 'release-0.5.5'