framer-802154: Support for creating and parsing frames with security headers
framer-802154: Support for setting and accessing the frame type
attribute
framer-802154: Sequence number fix
framer-802154: Renamed variable
framer-802154: Simplification of frame802154_create
framer-802154: Calling NETSTACK_LLSEC.on_frame_created()
framer-802154: Support for key identifiers (explicit key selection)
llsec: Configuration option for defining a constant LoWPAN-wide security level
llsec: Hardware-independent interface to the symmetric-key
algorithms of 802.15.4
llsec: Reusable LLSEC_CCM.aes-based implementations of CCM*
llsec: Reusable functions for settings keys that are smaller
than 128 bits and for calling AES with plaintext blocks that are
smaller than 128 bits
CC2420: Doing CRC in hardware all the time
CC2420: Macros as functions for saving program memory
CC2420: CC2420_WRITE_RAM with parameterizable ordering + resulting
simplifications
CC2420: The crystal oscillator only needs to stabilize on startup
CC2420: The variable "pending" was never used
CC2420: Removed unused variables
CC2420: Eliminated duplicated code in cc2420_read
CC2420: Reusing getrxdata instead of getrxbyte.
CC2420: Hardware security-based llsec802154_ccm_driver