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)
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.
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
net_help: prefix csum properly and add documentation
Merge pull request #2019 from authmillenon/cleanup-net_help

net_help: Cleanup
native: add fileno wrapper
native: disable interrupts for reboot
native: add "fildes" module (WIP)