more trivial cleanups

Hi Greg,
here are four remaining patches for udev.
You see 007 is in so good shape now, that I have nothing more exciting :)

It's a trivial whitespace/debug text cleanup, a simple format char simplification, a new test for udev-test.pl and a man page roundup.

I've added the textual id example for udev.permissions back to the man page, cause it's working now and mentioned klibc as the exception not glibc. Please have a look if this is fine with you.