Breaking Changes

updates to acomms_driver_node dynamic reconfigure which require rebuilding the package.
see !151 (merged) for details on breaking changes

New Features / Improvements

added interface to acomms_driver_node to allow sending ROS msg traffic in FDP ping payloads. To use, set ~use_ping_payload to True (default is False). To set the payload size pass: ~ping_maximum_miniframe_bytes (default is 32, max).
acomms_driver_node now sets the parameter server with the ~modem_config (which we now cache) after updating and setting the values for tx_inhibit and pwramp_txlevel.
modem_sim_node now supports same interface as acomms_driver_node for using the ping_payload to transport ros msgs. (no dynamic reconf for modem sim though)
- same rosparams used in the acomms_driver_node: ~use_ping_payload (default:false) ~ping_maximum_miniframe_bytes (default:32)