get rid of all urllib2 calls

ox/web/youtube.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 # vi:si:et:sw=4:sts=4:ts=4
-from urllib import quote, unquote_plus
-import urllib2
-import cookielib
+from six.moves.urllib.parse import quote, unquote_plus
+from six.moves import urllib
+from six.moves import http_cookiejar as cookielib
 import re
 from xml.dom.minidom import parseString
 import json
@@ -167,7 +167,7 @@ def download_webm(id, filename):
     stream_type = 'video/webm'
     url = "http://www.youtube.com/watch?v=%s" % id
     cj = cookielib.CookieJar()
-    opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj))
+    opener = urllib.request.build_opener(urllib.request.HTTPCookieProcessor(cj))
     opener.addheaders = [
         ('User-Agent',
          'Mozilla/5.0 (X11; Linux i686; rv:2.0) Gecko/20100101 Firefox/4.0'),