This one enables rw session support for Rescue images;
the nitpick is that syslinux' gfxboot *will* set this up
when booting the same ISO from USB Flash media instead of
optical one (CD/DVD-ROM/RW), and we don't put gfxboot into
a standalone rescue image.

See-also: http://altlinux.org/propagator
See-also: http://altlinux.org/remount_rw