pkg/emb6: Add random functions to rename patch

 gnrc_ipv6: clean-up and simplify send handling

This change is a gnrc_ipv6_nib/gnrc_netif(2)-based rework of #7210.

Packet duplication
==================

Its main optimization is that it restructures `gnrc_ipv6` handling of
sent packets so that duplication for write-protection happens at the
latest possible step:

* potential `gnrc_netif` headers added by upper layers are
  write-protected before their removal
* This unifies the duplication of the IPv6 header directly after
  that
* Extension headers in-between the IPv6 header and the payload header
  are duplicated just before the check sum is duplicated

Especially the last point allows for only handing a single packet snip
to all lower functions instead of an already searched IPv6 header
(which now is always the first until it is handed to the interface) +
payload header.

Further clean-ups
=================
* Next-hop link-layer address determination was moved to the
  `_send_unicast` function, greatly simplifying the unicast case in the
  `_send` function
* Code for loopback case was added to a new function `_send_to_self`
* Removed some code duplication

Both random_init and random_rand are prefixed with emb6_ to prevent
function name collisions with RIOT

lwip: explicitly set required netdev events

gnrc_netif_ieee802154: drop frame on buffer error

cc2538: use netdev reset

emb6: explicitly configure RX complete interrupt

    Cleanup netdev calls using &dev->netdev for all functions and
    thereby omiting the explicit cast.

netdev_ieee802154: Add and use common reset function

mrf24j40: Fix netdev recv implementation

openthread: Enable RX complete netdev event

dist/tools: update EDBG version

This adds a netdev recv call to indicate that the received frame should be
dropped when there is no buffer space available to store the frame.

The mrf24j40 driver should return the frame length when both buf is NULL
and len is zero and drop the packet when len is nonzero and buf is NULL.
This commit fixes that behaviour

Fixes issue where openthread assumed that this flag was enabled by
default with netdev devices

stm32: fix vendor header conflicting enum

remote: add RESET variable

tests/periph_uart: adapt main.c for automated testing

This is an effort to automate UART testing using the same framework as
was already introduced for i2c. The framework relies on shell commands
to return invocation status and data in a special way:

1. Invocation status: Success or Error
2. Data inside the []

Hence this patch adds invocation status to the UART init command and
invocation status and data to the printer.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>

gnrc_tcp: Add missing includes

Makefile.include: remove debug '$(info)'

Remove debug '$(info)' added by https://github.com/RIOT-OS/RIOT/pull/9451

make: Add 'BUILDDEPS' variable

make: fix dedup USEMODULE_INCLUDES in Makefile.include

    Fixes a regression introduces #9479 which breaks building on macOS.
    The introduces `uniq` function is never called, hence the includes
    ie. USEMODULE_INCLUDES are not used.