unify tranceiver shell commands

unified all existing transceiver commands in sc_transceiver.c
simplified the Makefile
use local variables for messages
only convert after checking for parameters existence
integrate OlegHahm@1d6aab8, fix description
review WIP
add transceiver command for DBG_IGN
change transceiver get_address return type to radio_address_t
fix ign handler

fix return value printing
fix build when DBG_IGNORE is not set, resolves: https://github.com/RIOT-OS/RIOT/pull/278#issuecomment-30058121