Ticket #3962: support Geeqie image viewer.

Use Geeqie (a fork of GQview) as main image viewer, fallback to GQview.

Signed-off-by: Andreas Mohr <and@gmx.li>
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

misc/ext.d/image.sh

@@ -40,7 +40,11 @@ do_open_action() {
         ;;
     *)
         if [ -n "$DISPLAY" ]; then
-            (gqview "${MC_EXT_FILENAME}" &)
+            if which geeqie >/dev/null 2>&1; then
+                (geeqie "${MC_EXT_FILENAME}" &)
+            else
+                (gqview "${MC_EXT_FILENAME}" &)
+            fi
         elif see >/dev/null 2>&1; then
             (see "${MC_EXT_FILENAME}" &)
         else