Wt

In #12320 the Cache-Control header could be added to the server, to control the maximum cache lifetime of static resources.
This would be applied globally to all statically server files.

However, this setting would only apply to Wt's own http server, and be limited to one global setting.
We should be able to configure this per resource. So that, if changes have occurred, the application can "force" the resource to be updated.

This is something that should be available independent of the used server backend (wthttp / fcgi / tomcat (for JWt)).

It can be done via an additional query string, like a version, modification timestamp or hash. Known as cache-busting.
The browser will see this additional query string, and consider the value unique, if the value does not correspond to a previous request, resulting in a new "fresh" pull of the resource.