Workaround for Ext JS store-sync-callback not called when no modifications took place

Somewhere back in time the `Ext.data.Store`-sync method got a callback-option which is called when the sync-operation completes. But this callback is not executed if there are no modifications to the store (no add, no delete, no update). Which seems a bit odd imho. If the codes relies on the callback beeing always executed whent the […]