title: Scrapy issue with iTunes' AppStore
body: <p>I am using Scrapy to fetch some data from iTunes' AppStore database. I start with this list of apps: <a href="http://itunes.apple.com/us/genre/mobile-software-applications/id36?mt=8" rel="nofollow noreferrer">http://itunes.apple.com/us/genre/mobile-software-applications/id36?mt=8</a></p>
  
  <p>In the following code I have used the simplest regex which targets all apps in the US store. </p>
  
  <pre><code>from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
  from scrapy.contrib.spiders import CrawlSpider, Rule
  
  class AppStoreSpider(CrawlSpider):
      domain_name = 'itunes.apple.com'
      start_urls = ['http://itunes.apple.com/us/genre/mobile-software-applications/id6015?mt=8']
  
      rules = (
          Rule(SgmlLinkExtractor(allow='itunes\.apple\.com/us/app'),
              'parse_app', follow=True,
          ),
      )
  
  def parse_app(self, response):
      ....
  
  SPIDER = AppStoreSpider()
  </code></pre>
  
  <p>When I run it I receive the following: </p>
  
  <pre><code> [itunes.apple.com] DEBUG: Crawled (200) &lt;GET http://itunes.apple.com/us/genre/mobile-software-applications/id6015?mt=8&gt; (referer: None)
   [itunes.apple.com] DEBUG: Filtered offsite request to 'itunes.apple.com': &lt;GET http://itunes.apple.com/us/app/bloomberg/id281941097?mt=8&gt;
  </code></pre>
  
  <p>As you can see, when it starts crawling the first page it says: "Filtered offsite request to 'itunes.apple.com'". and then the spider stops.. 
   it also returns this message:</p>
  
  <pre><code>[ScrapyHTTPPageGetter,client] /usr/lib/python2.5/cookielib.py:1577: exceptions.UserWarning: cookielib bug!
  </code></pre>
  
  <p>Traceback (most recent call last):
     File "/usr/lib/python2.5/cookielib.py", line 1575, in make_cookies
       parse_ns_headers(ns_hdrs), request)
     File "/usr/lib/python2.5/cookielib.py", line 1532, in _cookies_from_attrs_set
       cookie = self._cookie_from_cookie_tuple(tup, request)
     File "/usr/lib/python2.5/cookielib.py", line 1451, in _cookie_from_cookie_tuple
       if version is not None: version = int(version)
   ValueError: invalid literal for int() with base 10: '"1"'</p>
  
  <p>I have used the same script for other website and I didn't have this problem. </p>
  
  <p>Any suggestion? </p>