fix nativenet_send documentation
Merge pull request #472 from LudwigOrtmann/nativenet_send

fix nativenet_send documentation
make buildtest output coloured
Merge pull request #474 from OlegHahm/buildtest_coloroutput

make buildtest output coloured
Create transceiver address type

Motivated by the fact that we might want to support hardware addresses
longer than 16-bit one day. This patch makes it easier to change the
size of addresses.
Implement net_if module
Add shell commands for interface configuration