This way we also get a man page. The output is not as polished.
I hope that it doesn't matter too much.
index.html is not generated now, the page is called
systemd.index.html. If necessary, an install hook should be added.
This saves test output to individual .log files.
The driver is only used in /Makefile.am, not in
/docs/*udev/Makefile.am because the latter don't seem to work with
this driver. They don't produce much output anyway.
.gitignore is alphabetized, and .log files are added to it.
Generated files from /build-aux are removed from the list.