Add .htaccess for gzipped files

[szepeviktor]

Could start with W3TC main and page cache apache config:

# BEGIN W3TC Page Cache core
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteCond %{HTTP:Accept-Encoding} gzip
    RewriteRule .* - [E=W3TC_ENC:_gzip]
    RewriteCond %{HTTP_COOKIE} w3tc_preview [NC]
    RewriteRule .* - [E=W3TC_PREVIEW:_preview]
    RewriteCond %{REQUEST_METHOD} !=POST
    RewriteCond %{QUERY_STRING} =""
    RewriteCond %{REQUEST_URI} \/$
    RewriteCond %{HTTP_COOKIE} !(comment_author|wp\-postpass|w3tc_logged_out|wordpress_logged_in|wptouch_switch_toggle) [NC]
    RewriteCond "%{DOCUMENT_ROOT}/wp-content/cache/page_enhanced/%{HTTP_HOST}/%{REQUEST_URI}/_index%{ENV:W3TC_PREVIEW}.html%{ENV:W3TC_ENC}" -f
    RewriteRule .* "/wp-content/cache/page_enhanced/%{HTTP_HOST}/%{REQUEST_URI}/_index%{ENV:W3TC_PREVIEW}.html%{ENV:W3TC_ENC}" [L]
</IfModule>
# END W3TC Page Cache core

# BEGIN W3TC Page Cache cache
AddDefaultCharset UTF-8
<IfModule mod_mime.c>
    AddType text/html .html_gzip
    AddEncoding gzip .html_gzip
    AddType text/xml .xml_gzip
    AddEncoding gzip .xml_gzip
</IfModule>
<IfModule mod_setenvif.c>
    SetEnvIfNoCase Request_URI \.html_gzip$ no-gzip
    SetEnvIfNoCase Request_URI \.xml_gzip$ no-gzip
</IfModule>
# END W3TC Page Cache cache