mmem: Prevent duplicate init of mmem

This could seriously corrupt data if mmem_init was called again after
someone called mmem_alloc.
atmega128rfa1: Fix the default build error

Fixing from http://sourceforge.net/p/contiki/mailman/message/32494852/

Signed-off-by: Weichuan Yan <yan.weichuan@gmail.com>
Adding a scan-build command

scan-build http://clang-analyzer.llvm.org/scan-build.html is a clang
based tool designed to provide static analysis over C code files.
packetbuf: Added function "packetbuf_holds_broadcast()" for checking whether the current packet is a
broadcast
packetbuf: Use packetbuf_holds_broadcast() all-over
Seedeye platform: add the explicit list of modules
Changed sorting order of routing list (optimization).
ContikiMAC: Added missing length function to contikimac-framer.c
ContikiMAC: Retain original copyright
ContikiMAC: Default to contikimac_framer when using Rime over ContikiMAC
examples/ipv6/rpl-border-router: Add -DUIP_CONF_TCP=1 to CFLAGS

The example used to rely on the default value being set to 1 which
caused build failures on platforms which have a default UIP_CONF_TCP=0

Signed-off-by: Joakim Gebart <joakim.gebart@eistec.se>
Fixed rssi scanner application and moved into single example
Merge pull request #879 from alignan/fix_rssi_app

Fixed rssi scanner application and moved into single example
Merge pull request #877 from gebart/for-upstream/rpl-border-router-webserver-tcp

examples/ipv6/rpl-border-router: Add -DUIP_CONF_TCP=1 to CFLAGS
Merge pull request #875 from joakimeriksson/rtablefix

Changed sorting order of routing list (optimization).
Merge pull request #816 from kkrentz/contikimac-framer-fix

ContikiMAC framer fix
Merge pull request #812 from kkrentz/packetbuf-holds-broadcast

packetbuf_holds_broadcast()
Merge pull request #872 from Bocci83/master

Seedeye platform: add the explicit list of modules
Merge pull request #792 from wchyan/master

atmega128rfa1: Fix the default build error
Merge pull request #698 from sieben/scan_build

Adding static analysis through the scan-build command