fix urlparse monkeypatches for python 2.7.4. closes scrapy#144

Author: dangra

scrapy/xlib/urlparse_monkeypatches.py

@@ -1,7 +1,11 @@
-from urlparse import urlparse, uses_netloc, uses_query
+from urlparse import urlparse
 
-# workaround for http://bugs.python.org/issue7904
+# workaround for http://bugs.python.org/issue7904 - Python < 2.7
 if urlparse('s3://bucket/key').netloc != 'bucket':
+    from urlparse import uses_netloc
     uses_netloc.append('s3')
+
+# workaround for http://bugs.python.org/issue9374 - Python < 2.7.4
 if urlparse('s3://bucket/key?key=value').query != 'key=value':
+    from urlparse import uses_query
     uses_query.append('s3')