prepare HAL for kernel 2.6.16 mount change event replacement

[David Zeuthen]

> > Why don't
> > we just scrap that and start depending on 2.6.15 since it's going to be
> > out soon, before hal 0.5.6 anyway :-)
> 
> Yeah, I like to remove that too.

Yup, in the name of progress, we've depended on the latest and greatest
earlier, so let's just do this again.

Thanks,
David