C++11 extensions in header files

[jia200x]

Hi.

I'm having some warnings when trying to compile C++ RIOT with some header files.
For example, I added "net/netdev2.h" in riot_and_cpp and example and got errors like this:

/home/jialamos/RIOT/sys/include/net/netopt.h:225:17: error: comma at end of enumerator list [-Werror=pedantic]
     NETOPT_NUMOF,

Commas at the end of enumerator list are valid in C99, but seems not to be valid when linking with G++ and pedantic flag.
I'm using Gcc 4.8.4.

Anyone else with a problem like this?

[LudwigKnuepfer]

go there instead: #5561