- support draft-ietf-6tisch-6top-protocol-03
- maintain a sequence number per neighbor
- rename variables and constants
- reconsider file structure and file names
- make sf-simple part of example
- update sixtop/README.md
- add regression-tests for 6tisch
- apply C-DAC copyright notice
- bugfix + cleanup
tsch_packet_create_eb() is changed to build an Enhanced Beacon in the
packetbuf directly. Along with this, its signature is updated by
removing buf and buf_size from the argument list.