mmem: Prevent duplicate init of mmem

This could seriously corrupt data if mmem_init was called again after
someone called mmem_alloc.
[avr] added missing mcu parameter to ASFLAGS in order to enable assembler compilation
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>
core/net/rime/ipolite: stop ctimer and reset queuebuf pointer when canceling old send

Ipolite is used by netflood and route-discovery modules among others. If a route request is yet to be re-broadcasted and a local route discovery is started (interval == 0), the previous queuebuf used is freed but ctimer and queuebuf pointer is left unchanged. This causes corrupt route requests to be sent, invalid routing tables to be formed, memcmp() on NULL pointer on receive, and other undefined behavior.

Signed-off-by: Oskar Nordquist <oskar.nordquist@crlsweden.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
llsec: Fixed MIC length; reject unsupported security levels
Do not trigger global repair when forwarding error is detected
Rank error packet should not be forwarded
Drop forwarding error packet and send back DAO to originating parent
Force NUD on default routers
Fix doxygen prerequisites
Sort docdirs

Sorting docdirs is requierd to get reproducable results
Add doxygen regression testing
Add doxygen regression test to travis
Adjust number of errors to travis environment
Seedeye platform: add the explicit list of modules
Moved thread states from module to header
Changed sorting order of routing list (optimization).