* Emit disconnected event instead of error when ECONNRESET
ECONNRESET means the other side of the TCP conversation abruptly
closed its end of the connection.
If we get an ECONNRESET error from the proxy request and the
socket is destroyed this means that the client has closed
his connection, and emit this as an error can lead to
confusion and hacks to filter that kind of message.
I think that the best we can do is abort and emit another event,
so if any caller wants to handle with that kind of error, he can
by listen the disconnected event.
https://github.com/nodejitsu/node-http-proxy/issues/813
* code standards, move econnreset check, change ev name
Reasoning: Rack's request class [makes use of](https://github.com/rack/rack/blob/master/lib/rack/request.rb#L243) this HTTP header. Certain edge-case scenarios (proxying from ember-cli to a Rails backend) can be problematic without this header being present.
/cc @perlun, @jesjos
Web browsers automatically issue an OPTIONS request in advance of other
HTTP requests when the document's domain does not match the target in
order to facilitate Cross-Origin Resource Sharing. These requests are
forbidden from specifying a body and typically do not specify an
(unecessary) `Length` header.
Node.js automatically adds the `Content-Encoding: chunked` header value
to requests that do not specify a `Length` header. This makes proxied
OPTIONS requests from web browsers invalid.
Explicitly set the `Content-Length` header of all `OPTIONS` requests to
"0", disabling the default "chunked" encoding behavior [2].
[1] http://www.w3.org/TR/cors/
[2] http://nodejs.org/api/http.html
