Clean up generics a bit

impl ServerConnectorBuilder {

    /// Creates a new builder for server-side TLS connections.

    ///

    /// The default configuration is based off of the intermediate profile of Mozilla's SSL

    /// Configuration Generator, and is subject to change.

    pub fn tls<I, T>(private_key: &PKeyRef,

    /// The default configuration is based off of the intermediate profile of Mozilla's server side

    /// TLS configuration recommendations, and is subject to change.

    pub fn tls<I>(private_key: &PKeyRef,

                  certificate: &X509Ref,

                  chain: I)

                  -> Result<ServerConnectorBuilder, ErrorStack>

        where I: IntoIterator<Item = T>,

              T: AsRef<X509Ref>

        where I: IntoIterator,

              I::Item: AsRef<X509Ref>

    {

        ServerConnectorBuilder::new(SslMethod::tls(), private_key, certificate, chain)

    }

    fn new<I, T>(method: SslMethod,

    fn new<I>(method: SslMethod,

              private_key: &PKeyRef,

              certificate: &X509Ref,

              chain: I)

              -> Result<ServerConnectorBuilder, ErrorStack>

        where I: IntoIterator<Item = T>,

              T: AsRef<X509Ref>

        where I: IntoIterator,

              I::Item: AsRef<X509Ref>

    {

        let mut ctx = try!(ctx(method));

        ctx.set_options(ssl::SSL_OP_SINGLE_DH_USE | ssl::SSL_OP_CIPHER_SERVER_PREFERENCE);