cpu/nrf51822: added RTT driver implementation
board/pca10000: enabled RTT timer in periph_conf.h
ccnl: use correct packet type
tests/periph_rtt: added test for RTT drivers
ccnl: disable debug and fix warnings
mc1322x: some fixes in transceiver and ccnl
Merge pull request #1521 from OlegHahm/ccnl_fixes

ccn: minor fixes
Merge pull request #1598 from haukepetersen/add_nrf_rtt

cpu/board: added RTT driver for NRF51822
transceiver: fix check for existence

The transceiver check if it is already running when initializing.
However, this check was done by comparing its pid for >= 0, which is not
sensible anymore since valid PIDs only start at 1.
native: fix and improve term-valgrind flags
Merge pull request #1602 from OlegHahm/transceiver_init_pid_check

transceiver: fix check for existence
native: add stack smashing protection

When `DEVELHELP` is defined, add `-fstack-protector-all`.
board/pca1000[0|5]: enabled RNG peripheral
cpu/nrf51822: added RNG driver
Merge pull request #1603 from LudwigOrtmann/native-valgrindoptions

native: fix and improve term-valgrind flags
Merge pull request #1570 from LudwigOrtmann/native-ssp

native: add stack smashing protection
cpu/stm32f4: added random number generator driver
board/stm32f4discovery: enabled RNG driver
Merge pull request #1611 from haukepetersen/add_stm32f4_random

cpu/stm32f4: added random number generator driver
Merge pull request #1607 from haukepetersen/add_nrf_random

cpu/nrf51822: added random number generator driver