netdev: Introduce setter for event handler thread
[SQUASH ME] netdev: adapt tests
[SQUASH ME] tests: check if pid in receive callback is correct
[SQUASH ME] netdev: move from set_event_handler() method to member variable
[SQUASH ME] netdev: remove some now unnecessary changes
[SQUASH ME] nativenet: fix broken initializer
drivers/cc110x: Allow packet payload up to 255 bytes
drivers/cc110x: Adapt rx/tx to changed rcv event handling