cpu/nrf51822: fixed gpio driver
boards: added LED macro for pca1000 & yunjia-nrf
Copy some files from cpu/sam3x8e to cpu/cc2538.
Add the latest cc2538-bsl script from https://github.com/JelmerT/cc2538-bsl/commit/f3701a0
at86rf231: replace vtimer_usleep by hwtimer_wait

This fixes a bug where the callback to unlock the thread, put to sleep by
`vtimer_usleep` wouldn't be woken up due to overhead. Using hwtimer_wait
works for now, but this section will be replaced a driver refactor anyway.
cpu/stm32f1:board/iot-lab_M3: fix and cleanup for GPIO low level driver
cpu/stm32f1: overwrite HWTIMER_WAIT_OVERHEAD
udp: fix byte order in sockaddr6_t

udp_recvfrom wrote the sender port number in host byte order into the
provided sockaddr6_t. Because all send functions expect the port number
in network byte order this introduces a superfluous conversion step in
case one wants to reuse the address for replying.

closes #1406
examples: add extern "C" to header `rpl_udp.h`
net: Initial import of a packet wrapper for priority_queue
Merge pull request #1640 from authmillenon/packetqueue

net: Initial import of a packet wrapper for priority_queue
Merge pull request #1790 from BytesGalore/extern_C_in_headers_examples

examples: add extern "C" to headers
sys/net/pktqueue: fix doxygen
Merge pull request #1798 from LudwigOrtmann/pktqueue-doxygen

sys/net/pktqueue: fix doxygen
Merge pull request #1795 from sgso/byte-order-udp-sockaddr

udp: fix byte order in sockaddr6_t
Merge pull request #1720 from haukepetersen/fix_nrf_gpio

cpu/nrf51822: fixed gpio driver
Merge pull request #1722 from haukepetersen/fix_nrf_leds

boards: added LED macro for pca1000 & yunjia-nrf
Merge pull request #1756 from thomaseichinger/welq-fix

cpu/stm32f: boards/iot-lab_M3: cleanup and fixes
cpu/nrf51822: fixed issue with disabled RAM

- on certain devices the second RAM bank might be disabled after
  reset, this fix makes sure its enabled
Merge pull request #1804 from haukepetersen/fix_nrf_ram

cpu/nrf51822: fixed issue with disabled RAM