Find win7 partition; explain if can't find configfile

If someone uses "Auto-detect ISO's configfiles" or "Auto-detect bootable
partitions" and it doesn't find anything it just blinks and is
confusing, so this shows a message and waits 5 seconds.

This also searches for `/efi/microsoft/boot/bootdmgfw.efi` which should
be the efi boot file for a windows 7 installer.

mbusb.cfg

@@ -21,6 +21,7 @@ fi
 # Function to look for boot files
 function search_files {
   root="$1"
+  found=""
 
   insmod bitmap
   insmod jpeg
@@ -33,6 +34,7 @@ function search_files {
     /boot/grub/x86_64-efi/grub.cfg \
     /EFI/BOOT/grub.cfg; do
     if [ -e "$grubfile" ]; then
+      found="found"
       menuentry "GRUB boot ($grubfile)" "$grubfile" {
         grub_file="$2"
         configfile "$grub_file"
@@ -52,6 +54,7 @@ function search_files {
     /boot/syslinux/isolinux.cfg \
     /boot/syslinux/syslinux.cfg; do
     if [ -e "$syslinuxfile" ]; then
+      found="found"
       menuentry "SYSLINUX boot ($syslinuxfile)" "$syslinuxfile" {
         syslinux_file="$2"
         syslinux_configfile -i "$syslinux_file"
@@ -63,6 +66,7 @@ function search_files {
     /boot/grub/menu.lst \
     /menu.lst; do
     if [ -e "$legacyfile" ]; then
+      found="found"
       menuentry "GRUB legacy boot ($legacyfile)" "$legacyfile" {
         legacy_file="$2"
         legacy_configfile "$legacy_file"
@@ -71,15 +75,22 @@ function search_files {
   done
 
   if [ "x$grub_platform" == "xefi" ]; then
-    for efifile in /efi/boot/bootx64.efi; do
+    for efifile in \
+      /efi/boot/bootx64.efi \
+      /efi/microsoft/boot/bootdmgfw.efi; do
       if [ -e "$efifile" ]; then
+        found="found"
         menuentry "EFI boot ($efifile)" "$efifile" {
           efi_file="$2"
           chainloader "$efi_file"
         }
       fi
     done
   fi
+  if [ "x$found" == "x" ]; then
+    echo "no bootable things found on $root"
+    sleep -v -i 5
+  fi
 
 }