Export header values

When exporting a configuration version, you can specify these headers:

Accept
Accept-Charset
Accept-Encoding
Accept-Language
Accept-Ranges
Access-Control-Allow-Origin
Age
Allow
Cache-Control
Connection
Content-Disposition
Content-Encoding
Content-Language
Content-Length
Content-Location
Content-MD5
Content-Range
Content-Security-Policy
Content-Type
DNT
Date
Etag
Expect
Expires
From
Host
If-Match
If-Modified-Since
If-None-Match
If-Range
If-Unmodified-Since
Last-Modified
Link
Location
Max-Forwards
Origin
P3P
Pragma
Proxy-Authenticate
Range
Referer
Refresh
Retry-After
Server
Strict-Transport-Security
TE
Trailer
Transfer-Encoding
Upgrade
User-Agent
Vary
Via
WWW-Authenticate
Warning
X-Content-Security-Policy
X-Content-Type-Options
X-Forwarded-For
X-Forwarded-Proto
X-Frame-Options
X-Powered-By
X-Requested-With
X-UA-Compatible
X-WebKit-CSP
X-XSS-Protection