Fix etc-update and config-protect.

Fix etc-update and config-protect.
Because the profiles contain CONFIG_PROTECT variables, they cannot be
prefixed without defining variables there.  Hacking portage to only
prefix those paths from the profiles is a bit ugly (and hard), so
instead it was decided (like Kito already decided once long ago) that
CONFIG_PROTECT paths are non-prefixed, as the only exception in the
system.  This means that no corrections need to be done, and that when
the paths are being used they have to be prefixed.

svn path=/main/branches/prefix/; revision=4717