Added question about boot.flp hanging on an ASUS K7V motherboard, and the
workaround (disable BIOS boot sector virus check).

Submitted by: Discussion on -stable

Add 4.0 to a few places. Update the "Panic: can't mount root!" now we
have a new boot loader. Add an "Error: can't find libc.so.4" and a
"How do I upgrade from 3.x to 4.x" question.

Fix a few typos in the PR.

PR: docs/17861
Submitted by: Eric Ogren <eogren@earthlink.net>

Add a little bit of extra information about chmod(1) on symlinks, so that
the questions are a little bit clearer.

Suggested by: Suresh Bhushan <sbhushan@smartshop.com>

Reword the "snd0" answer, to make it clearer.

Submitted by: gouders@et.bocholt.fh-gelsenkirchen.de