Avoids confusion with generic CoAP and capitalization retains order
in documentation.

Otherwise, there will be leaks ;-).

Otherwise, there will be leaks ;-).

When issueing the sending of the next fragment the current version of
`gnrc_sixlowpan_frag` doesn't check if the queue is full. This leads to
leakage of the packet buffer, since when it is full, the package never
gets released.

This change adds a checks and error exits in case the queue is full.

The current implementation uses the assumption that the IPv6 address is
always based on an EUI-64, which it doesn't has to.

The RN2xx3 device has this parameter in milliseconds. So far, there is no
other device driver using loramac.h

Notice that RN2xx3 only has a get command for rxdelay2, not a set command.
Nevertheless, that parameter was changed to milliseconds as well.

This module adds some helper function to manage slots
created with a riotboot_hdr header.

Co-authored-by: Kaspar Schleiser <kaspar@schleiser.de>

It's a lot cleaner and makes more sense if we merge those two.

They are also defined in `net/gnrc/netif/mac.h` and those are the ones
used by the current `gnrc_mac` implementations.

This adds `GNRC_NETIF_FLAGS_RAWMODE` to the `net_gnrc_netif_flags_t`
group.