pkg/oonf_api: fix conflicting types on msba2
unittests: core: add test_bitarithm_[ml]sb_all
Add test_ipc_pingpong
Add bitarithm measuring
core: faster bitarithm_msb
native: use `real_pipe()` and `read_close()`
Merge pull request #1210 from benpicco/fix_oonf_msba2

pkg/oonf_api: fix conflicting types on msba2
Merge pull request #975 from Kijewski/issue-974

core: change in bitarithm implementation
Merge pull request #1322 from Kijewski/native-pipe-and-close

native: use `real_pipe()` and `read_close()`
cpu - cortex-m3: moved crash.c to cortex-m3_common
Merge pull request #1327 from haukepetersen/fix_cortexm3_crash

cpu - cortex-m3: moved crash.c to cortex-m3_common
lpc2387: change comment style for license checker
cortex: change comment style for license checker
lpc2k: unify Paul Stoffregen license headers
SQUASHME: change to lgplv2.1 header

Addresses https://github.com/RIOT-OS/RIOT/pull/1314#discussion_r13650324