Moves lwIP to an integration scheme more similar to newer `pkg`s.

Fixes #7707
Fixes #7800

With out this fix the application or device drivers need to add this
module. Otherwise, compilation of the lwIP adaptation layer will fail
for Ethernet devices.

`sock_util` includes the `arpa/inet.h` header so it has `posix` as a
dependency to include the `sys/posix/include` include path.

When I introduced this pseudo-module in #9391 I did not consider, that
the way I named it, it is assumed to be an implementation of the
`gnrc_pktbuf` interface. However, it is not (it just provides the shell
command).

This PR excludes `gnrc_pktbuf_cmd` from the selection algorithm, so
that if it is the only `gnrc_pktbuf_%` module, still
`gnrc_pktbuf_static` gets selected.

Provides functions for type 3, 4 and 5 UUID generations.

UUID type 1 is timestamp based and requires an accurate time source. For
this reason it is left out of this implementation. UUID type 2 is not
defined in RFC 4122 and thus also not included here

- Cleanup package makefile.
- Download directly from git.
- Remove giant patch.
- Implement malloc function as a contrib package.
- Update ccn example.
- Update ps command.

Currently, the arduino module depends on the "cpp" feature. As AVR's
don't have libstdc++, they don't provide that feature, as otherwise all
cpp examples would break.  But the AVR does provide a cpp compiler and
thus the arduino module compiles just fine.

This comit removes the cpp dependency from arduino module.

Skald is a very small and simple, TX-only BLE stack that supports
sending advertisements only. It is useful for building all kinds
of BLE beacons with very minimal memory footprints.

Fits larger values into the 16 bit integers used by phydat and update
scale accordingly.

Add a warning message in user's console to inform them routing capabilities will
be disabled with the softdevice