Some editors automatically remove trailing blank lines, or
automatically add a trailing newline to avoid having a trailing
non-blank line that is not terminated by a newline. To avoid unrelated
whitespace changes when users of such editors contribute to dbus,
let's pre-emptively normalize all files.

Unlike more intrusive whitespace normalization like removing trailing
whitespace from each line, this seems unlikely to cause significant
issues with cherry-picking changes to stable branches.

Implemented by:

    find . -name '*.[ch]' -print0 | \
    xargs -0 perl -0777 -p -i -e 's/\n+\z//g; s/\z/\n/g'

Signed-off-by: Simon McVittie <smcv@collabora.com>