tests: fix netdev test
Merge pull request #1761 from authmillenon/netdev-fix

tests: fix netdev test
cpu/stm32f0: removed leftovers from slave mode
Merge pull request #1713 from haukepetersen/fix_stm32f0_spi

cpu/stm32f0: removed leftovers from slave mode
nativenet: Apply coding conventions
nativenet: Supply net_dev_t support for nativenet