As RFC 2616 says we should, assume that servers will provide a persistent
connection by default.
> A significant difference between HTTP/1.1 and earlier versions of
> HTTP is that persistent connections are the default behavior of any
> HTTP connection. That is, unless otherwise indicated, the client
> SHOULD assume that the server will maintain a persistent connection,
> even after error responses from the server.
> HTTP/1.1 applications that do not support persistent connections MUST
> include the "close" connection option in every message.
Fixes#2436.
isaacs
koichik