busybox

- pass "Accept:" and "Accept-Language:" header to CGI scripts (Alina Friedrichsen)

Alina writes:
With this patch the BusyBox httpd pass the "Accept:" and
"Accept-Language:" header by the environment variables to the
CGI-Script, so this can make Content Negotiation to deliver the page in
the language, which was selected by the user in the browser settings,
and/or serve the XHTML page with the right MIME-Type
application/xhtml+xml to user agents which support it und text/html
which don't.

(Needed e.g. for OpenWrt LuCI.)

Signed-off-by: Alina Friedrichsen <x-alina at gmx dot net>