samr21: implemented transceiver via spi, gpio changes
Merge pull request #1997 from Troels51/samr21-transceiver-port

samr21: implemention of transceiver via spi
add parentheses to ENABLE_DEBUG in CBOR_NO_PRINT
Merge pull request #2208 from Lotterleben/cbor_add_define_parentheses

add parentheses to ENABLE_DEBUG in CBOR_NO_PRINT
fix typos in ip.h, mac.h, ndp.h and types.h
Merge pull request #2210 from Lotterleben/fix_sixlowpan_typos

fix typos in ip.h, mac.h, ndp.h and types.h