[SQUASH ME] netapi: address @OlegHahm's comments + some formatting
[SQUASH ME] netapi: add demuxing context to reg command
[SQUASH ME] netapi: make current_thread registration inline
Merge branch 'network-layer-interface' into 6lowpan-fix-major
[SQUASH ME] sixlowpan.core: adapt to registry context
[SQUASH ME] add test execution script and target