cpu/stm32f4: optimized GPIO driver implementation
SQUASH: cpu: fixed some typos
SQUASH: cpu/f4: changed order of irq enabling seq
ccn-lite: use always ccnl_malloc
cpu/nrf51822: added HFCLK initialization
boards: added CLOCK defines to NRF based boards
cpu/samd12: c++: initial support for c++, added _kill (weak) and weak attribute for _kill_r
boards/samr21-xpro: provided c++ feature (cpp)
cpu/stm32f0: c++: initial support for c++, added _kill (weak) and weak attribute for _kill_r
boards/stm32f0discovery: provided c++ feature (cpp)
native: add accept syscall declaration
native: shutdown -> native_shutdown
native: add more syscall declarations
net_help: remove printArrayRange()

The od module does the same, much less specialized, much more
sophisticated.
net_help: remove IPV6_CMP_ADDR macro

Used nowhere; alternative: ipv6_addr_is_equal(), since other use-cases
(is an IPv6 address smaller than the other) are not applicable anyway.
FIXUP: remove erroneous comment
native: add daemonize argv filter

When daemonizing, only the first instance should do so.
Merge pull request #2020 from LudwigOrtmann/native_daemonize_filter

native: add daemonize argv filter
Merge pull request #2002 from OlegHahm/ccnl_malloc_all_over

ccn-lite: use always ccnl_malloc
Merge pull request #2015 from LudwigOrtmann/native_real-accept

native: add missing syscall declarations
Merge pull request #1994 from BytesGalore/EasyCPPMixing_samr21_xpro_support_fix

cpu/samd21 C++ samr21-xpro support fix
Merge pull request #1987 from BytesGalore/EasyCPPMixing_stm32f0discovery_support_fix

cpu/stm32f0 C++ stmf0discovery support fix