As of 2.5LTS we require Varnish 5.1 or higher, which means people need to use newer versions of varnish-modules as well that support these Varnish versions.

Meaning we can take advantage of varnish-modules 0.10.x support for several keys in header while purging. In order to:

• Simplify Varnish debugging when checking purge requests
• Reduce rountrips on between web server and varnish for purges

Given the package is technically also allowed to be used on 1.13, which was released with Varnish 4.x support. Either we should
A. expose a setting for this
B. Users of 1.13 + Varnish 4 will need to use ezplatform-http-cache 0.8.x.