sys/posix: factor inet_*to* from header into .c file

sys/net: add common lora phy definitions

tests/netstats_l2: migrate to testrunner

unittests: update boards lists

testrunner: make traceback extraction downwards-compatible

The object-like access to frame information in the traceback was only
introduced in Python 3.5. Before that version it was a 4-tuple [[1]].

The indexed way to access the frame seems to be upwards-compatible for
newer versions (tested with python 3.5, maybe some of the Arch crew can
test with even newer versions), so I used that one.

[1]: https://docs.python.org/3.4/library/traceback.html#traceback.extract_tb

tests/pkg_8g2: migrate to testrunner

cpu/nrf52: added ADC driver implementation

tests/fmt_print: migrate to testrunner

tests/periph_timer: migrate to testrunner

test: periph_timer: check if argument is passed.

tests/thread_msg: migrate to testrunner

cpu + boards: add support for thunderboard sense

od: add ASCII representation

periph/rtc: move init from auto_init to periph_init

examples/pkgs: rename modules with duplicate names

dist/tools/pr_check: fix regex pattern to recognize any SHA

Root directory of libfixmath and u8g2 where the same as another directory.

examples/default: remove usage of config module

cpu/sam0: share GPIO configuration

makefiles: docker: make docker call non-interactive