llsec: Added a layer in between NETSTACK_MAC and NETSTACK_NETWORK for implementing link layer security
llsec: Configuration option for defining a constant LoWPAN-wide security level
sky-main: Calling NETSTACK_LLSEC.bootstrap from contiki-sky-main.c
sky-main: DEBUG on/off switch
packetbuf: Made packetbuf_hdrlen applicable to inbound packets, too
framer-802154: Style fixes
framer-802154: Introduced mnemonic variable
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 for the sake of consistency
framer-802154: Simplification of frame802154_create
framer-802154: Conditional compilation of security-related code
framer-802154: Support for explicit keys
llsec: Calling NETSTACK_LLSEC.on_frame_created()
llsec: Hardware-independent interface to AES
llsec: Reusable LLSEC802154_AES-based implementation of CCM*
llsec: Reusable functions for settings keys that are shorter
than 128 bits and for calling AES with plaintext blocks that are
smaller than 128 bits
llsec: Software-based llsec802154_aes_driver
llsec: CCM* verification tests