在iOS連線中，保留session

只需要將cookie存在cookieStorage裡即可

- (NSData *)send:(NSHTTPURLResponse**)urlResponse
{
    NSError *errorState = nil;
    NSData *result = [NSURLConnection sendSynchronousRequest:request returningResponse:urlResponse error:&errorState];
    
    // process cookie
    NSArray *allCookies = [NSHTTPCookie cookiesWithResponseHeaderFields:[*urlResponse allHeaderFields] forURL:[*urlResponse URL]];
    if ([allCookies count]) {
        [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:allCookies forURL:[*urlResponse URL] mainDocumentURL:nil];
    }

    return result;
}