The SKIP_PAYLOAD stage of decoders would not read the last word
(last_word_in = '1').
The <NAME>_MEMBER_END stage was removed from encoders/decoders, since it
could happen that the last aggregated member of a last collection entry
could also be the last type member overall, which would miss toggling
the "last_word_out" correctly. The logic was instead put inside the last
member stage (instead of defining a separate MEMEBR_END stage).
All the necessary "glue" logic to convert ROS Data to a form that the
DDS/RTPS back-end can use is implemented in packages.
The ROS Node discovery information is statically generated in packages
(similar to the RTPS Participant Data), and a special dds writer is
implemented (ros_static_discovery_writer) that has this static data as
its only payload sample.
Some definitions are moved out of rtps_config_package to prevent
circular package dependency.
