Add automated filesystem checking based on scripts I've used now for

quite some time locally. Most of the test require root so they are
	skipped when run without necessarry privelegies.

tests/minixfs_test.in

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+set -e
+
+if [ "x$EUID" = "x" ] ; then
+  EUID=`id -u`
+fi
+
+if [ "$EUID" != 0 ] ; then
+   exit 77
+fi
+
+if ! which mkfs.minix >/dev/null 2>&1; then
+   echo "mkfs.minix not installed; cannot test minixfs."
+   exit 77
+fi
+
+if ! mkfs.minix -h | grep -- -v > /dev/null; then
+    echo "mkfs.minix doesn't support minix3fs; cannot test minix*fs."
+   exit 77
+fi
+
+"@builddir@/grub-fs-tester" minix
+"@builddir@/grub-fs-tester" minix2
+"@builddir@/grub-fs-tester" minix3