Set static html fragments as cacheable

[paveq]

Fixes issue where some of static content (knockout templates) are retrieved again for every request from the server, depending on apache configuration. With this modification we no longer depend on specifics of environment apache configuration.

[magento-cicd2]

All committers have signed the CLA.

[paveq]

I believe one failing integration test has nothing to do this with PR, and it related to something else.

[paveq]

What do you think, should we also send Cache-Control public for html files?

<FilesMatch .*\.(ico|jpg|jpeg|png|gif|svg|js|css|swf|eot|ttf|otf|woff|woff2)$>
    Header append Cache-Control public
</FilesMatch>

[maghamed]

We are accepting current pull request, but in future this behavior would be modified in Magento as Varnish should not be used for caching and serving static content as html, images, css and other media.
All these content types should be served from webserver cache (Nginx for example).

[paveq]

@maghamed Does not this relate to where Varnish layer is? In case of Varnish residing in the same server/DC not caching static content there can make sense, but what in case where Varnish layer in in the edge (eg. Fastly service) and used as CDN?

[okorshenko]

@paveq Thank you for your contribution! PR number == 8000 :) Good catch!