add HTTP "Cache-Control: immutable" headers for JS files
see: Comptoir/Comptoir-srv#796 (closed)
Added HTTP "Cache-Control: immutable" headers for CSS and JS files to use the browser's cache to the maximum.
- For Firefox, thhe HTTP "Cache-Control: immutable" header will be honored only if the content is served in HTTPS.
- Chrome does not actually support immutable at the moment, but has its own new heuristics
Documentation:
<IfModule mod_headers.c>
# <FilesMatch "\.(js|css)$">
<FilesMatch "\.js$">
Header set Cache-Control "public, max-age=31536000, immutable"
</FilesMatch>
</IfModule>