core/net/uip.h: Add missing #include <string.h>

Fixes implicit definition of memcmp() warnings/errors.

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
Remove the unmaintained iris platform
Fix code style in rpl_set_root prototype
Make DODAG ID selection RFC 6550-compliant

Some calls to `rpl_set_root` select a hardcoded DODAG ID
(0x1111, 0x1100, 0, 0, 0, 0, 0, 0x0011)

This is against what RFC 6550 says. We change these calls
to select a DODAG ID corresponding to a routable v6 address
corresponding to the root
Merge pull request #725 from oliverschmidt/master

Enhanced Ethernet drivers.
Merge pull request #713 from adamdunkels/pr/drop-iris

Remove the unmaintained iris platform
Re-create a routing table entry if the next hop is changed.

The next-hop address did not get updated in the routing table
in case an entry for the destination already existed.

This patch resolves the issue by removing the entry and
having it re-created from scratch.

The issue causes a routing error triggering reconstruction of
the DODAG through version increase.

In case of somewhat frequent downward traffic in not (yet) stabilized DODAG
a vicious circle is formed: unstable topology means churn, downward
routing under churn causes reconstruction of DODAG. In this situation
the network does not have chance to stabilize.

We encountered a constant churn caused by this bug
in a network of 50 nodes and a periodic traffic (a packet every 5
seconds) generated at the root.

More info and a PCAP demonstrating the issue can be found here:
https://github.com/contiki-os/contiki/issues/496
Merge pull request #701 from tim-ist/routing_fix

Re-create a routing table entry if the next hop is changed.
Merge pull request #718 from g-oikonomou/rpl-dodagid-compliance

Make DODAG ID selection RFC 6550-compliant
Added flags to enable 20-bit support from msp430-gcc 4.7.x
Fix SDCC Compile Error
Merge pull request #729 from g-oikonomou/fix-nd6-sdcc

Fix SDCC Compile Error
Merge pull request #637 from alignan/z1-add-flags-20bit-support

Added flags to enable 20-bit support from msp430-gcc 4.7.x
Sender rank in Hop-by-Hop option has inverted bytes
Setting uip_ext_len again breaks hop-by-hop option
Insert properly Hop-by-Hop option at first hop
Improve RPL hop-by-hop option detection
Merge pull request #650 from cetic/pr-rpl-hbh-fixes

Fix for RPL Hop-by-Hop options
rl78: Change RIMEADDR_CONF_SIZE to LINKADDR_CONF_SIZE because the rimeaddr module has been renamed to linkaddr.
Merge pull request #734 from hexluthor/rl78-linkaddr

rl78: Change RIMEADDR_CONF_SIZE to LINKADDR_CONF_SIZE