e - fm - flush all evas caches to get rid of open file handles b4 umount

this should fix open file handles on unmount by flushing caches first.
not great, but works. long-term have evas not keep file handles open
for 0 refcount cached items.

src/bin/e_fm.c

@@ -2611,6 +2611,15 @@ _e_fm2_client_unmount(const char *udi)
 
    _e_fm2_client_get();
 
+   elm_cache_all_flush();
+   edje_file_cache_flush();
+   edje_collection_cache_flush();
+   if (e_comp_get(NULL))
+     {
+        evas_image_cache_flush(e_comp_get(NULL)->evas);
+        evas_font_cache_flush(e_comp_get(NULL)->evas);
+     }
+
    return _e_fm_client_send_new(E_FM_OP_UNMOUNT, (void *)d, l);
 }