introduced support for two new response headers
And for two new request headers
Unfortunately on Project Index pages (also Component and Version indexes), whilst the E-Tag will update if Project properties (description, name, url etc) change, the Last-Modified date doesn't.
This is an issue, because some downstream caches (NGinx being one) only use If-Modified-Since when revalidating. So although the page content has changed, the page will revalidate.
There isn't actually a good way to get around this, as JIRA doesn't keep a log of when project/version/component properties were changed. So there isn't a date in the database we can extract to identify the most recent change (unless an issue has changed, then we can use that).