output ref_count in object summary

tiny Vips.py fix too

libvips/iofuncs/object.c

@@ -1473,6 +1473,7 @@ vips_object_real_summary_class( VipsObjectClass *class, VipsBuf *buf )
 static void
 vips_object_real_summary( VipsObject *object, VipsBuf *buf )
 {
+	vips_buf_appendf( buf, " count=%d", G_OBJECT( object )->ref_count );
 }
 
 static void

python/Vips.py

@@ -751,7 +751,7 @@ class Image(Vips.Image):
         # image-ize
         if GObject.type_is_a(gtype, vips_type_image):
             if not isinstance(value, Vips.Image):
-                value = imageize(match_image, value)
+                value = imageize(self, value)
 
         # array-ize some types, if necessary
         value = arrayize(gtype, value)