with help from include-what-you-use (iwyu-tool). It's not quite clever
enough to understand our intent of including "hal_include.h" but still
offers good suggestions.
Use tabs for leading whitespace and spaces for continuation lines.
Besides that inconsistent whitespace looks odd, it causes unnecessary
merge conflicts.
The project uses tabs with a length of 4 spaces, and spaces for
continuation, so lets use that for the whole project. There are
many trailing whitespaces and empty lines here and there; get
rid of them as well.
Some files have Windows line endings which is annoying, since pathes
won't apply, diffs looks ugly etc. So do convert the few files which
have Windows line endings to use Unix line endings as well.
