Move gnomeos/ to "gnome-ostree" module

Now that we're hopefully going to be changing the format less.  The
layering here is now more clear, rather than having things entangled.

src/ostadmin/15_ostree

@@ -0,0 +1,66 @@
+#!/bin/sh
+
+set -e
+
+. /usr/lib/grub/grub-mkconfig_lib
+
+CLASS="--class gnu-linux --class gnu --class os"
+
+if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
+    || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
+    || uses_abstraction "${GRUB_DEVICE}" lvm; then
+  LINUX_ROOT_DEVICE=${GRUB_DEVICE}
+else
+  LINUX_ROOT_DEVICE=UUID=${GRUB_DEVICE_UUID}
+fi
+
+ostree_linux_entry ()
+{
+  os="$1"
+  version="$2"
+  args="$3"
+
+  printf "menuentry '${os}; Linux ${version}' ${CLASS} {\n"
+
+  cat << EOF
+	insmod gzio
+EOF
+
+  cat <<EOF
+	echo '"Loading ${os} ${version}"'
+	linux ${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro ostree=current ${args}
+EOF
+  if test -n "${initrd}" ; then
+    message="$(gettext_printf "Loading initial ramdisk ...")"
+    cat << EOF
+	echo	'$message'
+	initrd	${rel_dirname}/${initrd}
+EOF
+  fi
+  cat << EOF
+}
+EOF
+}
+
+kernels=$(echo /boot/vmlinuz-*)
+while [ "x${kernels}" != x ]; do
+  linux=`version_find_latest $kernels` >&2
+  basename=`basename $linux`
+  dirname=`dirname $linux`
+  rel_dirname=`make_system_path_relative_to_its_root $dirname`
+  version=`echo $basename | sed -e "s,^[^0-9]*-,,g"`
+  alt_version=`echo $version | sed -e "s,\.old$,,g"`
+  linux_root_device_thisversion="${LINUX_ROOT_DEVICE}"
+
+  initrd=
+  for i in "initramfs-ostree-${version}.img" "initramfs-ostree-${alt_version}.img"; do
+    if test -e "${dirname}/${i}" ; then
+      initrd="$i"
+      ostree_linux_entry "GNOMEOS 3.4" "${version}" \
+	        "${GRUB_CMDLINE_LINUX}" "${GRUB_CMDLINE_LINUX_DEFAULT}"
+      break
+    fi
+  done
+
+  kernels=`echo $kernels | tr ' ' '\n' | grep -vx $linux | tr '\n' ' '`
+done