1. configure a salt for org.zkoss.zk.ui.versionInfo.enabled
2. load a resource from CWR e.g.
<?link rel='stylesheet' href="~./css/common.css"?>
the version hash in static CWR resource urls doesn't change
the salt should affect the version hash (obfuscating the version and allow cache busting)
the already works for dynamically loaded wpd resources
NOTE: don't forget to update the version string between your releases (if you want to use this for cache busting)