This is aimed to make the usage code of this module more readable.

The stack might still wants to do something with the packet after
copying it to the error message.

gnrc/pkt: Add const keyword to length functions

sys/crypto: optimize AES footprint (resurrected)

USEMODULE += crypto_aes_precalculated enables the precalculated T tables (the old
code).
USEMODULE += crypto_aes_unroll causes loops to be unrolled.

ethos: Only accept frame if previous frame is read

cpu/nrf5x: fix hwrng hang

gnrc_pktbuf: deprecate gnrc_pktbuf_duplicate_upto

Release 2018.10 notes

{drivers/saul,sys/phydat}: Added RSSI sensor and dBm unit

crypto/ccm: fix auth_data_len check

gnrc_sock_[udp|ip]: read return value for _recv after release

Maximal supported value is 0xFEFF.

RFC3610 states that len_encoding is only valid for "0x0001 ... 0xFEFF"

   If 0 < l(a) < (2^16 - 2^8), then the length field is encoded as two
   octets which contain the value l(a) in most-significant-byte first
   order.

Return value was ignored but function could fail

sock_[udp|ip]_recv returns `pkt->size` after pkt was released via `gnrc_pktbuf_release(pkt)`.
This can result in wrong values returned by this functions and thus is not according to its sepecification.

Storing this values before releasing pkt returning the stored values should fix this.

print_toolchain_versions.sh: Add make command version

gnrc_ipv6_nib: provide interface on packet queueing