Added dependencies to orocos_generate_package() calls

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Removed explicit calls to catkin_package()

This requires patch https://github.com/orocos-toolchain/rtt/commit/2103f2912be1a32eafbbd6ae41bdde98966d890f in rtt.

Signed-off-by: Johannes Meyer <johannes@intermodalics.eu>
Merge pull request #2 from meyerj/orocos-generate-package-cleanup

rtt_ros_comm: orocos_generate_package() cleanup