- 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
The argument, "type", is not used effectively in create_frame(). In
addition, it's confusing because create() calls create_frame() with
FRAME802154_DATAFRAME as "type" though it does not always create a data
frame.
