* Recommend persistent=nofiles instead of persistent without arguments.
* Clarify debs and scripts bootoption.
* Drop kernel bootoptions from main bootoptions (grml2ram, debug) -
it's confusing if they are listed under the bootoptions that can
be used in the graphical boot menu, whereas the kernel bootoptions
are meant for isolinux prompt only.
Thanks: Ulrich Dangel <mru@grml.org>