Handle urllib's renaming for Python 3.0:

* Deprecate urllib.urlopen() in favor of urllib2.urlopen() for 3.0.
* Update docs to mention split/rename of the module and deprecation of
  urlopen().

Changes to lib2to3 are in a separate commit. Work is for issue #2885.
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
index 61e0202..1dcbbed 100644
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -640,16 +640,20 @@
 
 
 def test_main():
-    test_support.run_unittest(
-        urlopen_FileTests,
-        urlopen_HttpTests,
-        urlretrieve_FileTests,
-        QuotingTests,
-        UnquotingTests,
-        urlencode_Tests,
-        Pathname_Tests,
-        #FTPWrapperTests,
-    )
+    import warnings
+    with test_support.catch_warning(record=False):
+        warnings.filterwarnings('ignore', ".*urllib\.urlopen.*Python 3.0",
+                                DeprecationWarning)
+        test_support.run_unittest(
+            urlopen_FileTests,
+            urlopen_HttpTests,
+            urlretrieve_FileTests,
+            QuotingTests,
+            UnquotingTests,
+            urlencode_Tests,
+            Pathname_Tests,
+            #FTPWrapperTests,
+        )