So we don't need to write so many edge case tests ourselves for things
like parsers, which really don't need those manual tests, as long as we
can check for some properties like "can output the parsed data and it'll
be the same as the input".
It doesn't work at all, because we're missing something in the net code
to do with endian conversions. I haven't investigated, yet, but at least
now we have a failing test that can be investigated.
Also moved to cmake 3.5 at minimum. CMake will stop supporting lower
versions than that, soon.
Also moved to C11 from C99 to get `static_assert`.
Also made a network ERROR into a WARNING. It triggers on FreeBSD.
This uses mallocfail to further increase coverage using the existing
tests. Also:
* Moved the non-auto "tox_one_test" to gtest. This should be
split into smaller tests later.
* Changed `hole_punching` to `bool`.