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* ais.decode now requires the pad bits in python
* Added RIS 8_200_{10,23,24,40,55}
* Implmented the rest of Circ 236 BBM
* Implmented all Circ 289 messages except ABM route and BBM env sensors
* Implemented AIS messages 6, 9, 10, 12, 15-17, 20-22, 23, 25-27. Still payload work to do.
* Imported rolker's CMakeList.txt