Support for MEMDISK

The .iso can now be booted using Grub (memdisk from Syslinux package):

	linux16 /memdisk
	initrd16 /path/to/iso

As well as from Syslinux:

	LINUX memdisk
	INITRD path/to/iso

dracut/mtd.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+MEMDISK=$(memdiskfind)
+if [ "$MEMDISK" ]; then
+	modprobe phram phram=memdisk,$MEMDISK
+	modprobe mtdblock
+	printf 'KERNEL=="mtdblock0", RUN+="/sbin/initqueue --settled --onetime --unique /sbin/dmsquash-live-root /dev/mtdblock0"\n' >> /etc/udev/rules.d/99-live-squash.rules
+fi