Documentation tweaks.

Author: SimonSapin

docs/conf.py

@@ -248,4 +248,6 @@
 
 
 # Example configuration for intersphinx: refer to the Python standard library.
-intersphinx_mapping = {'http://docs.python.org/': None}
+intersphinx_mapping = {
+    'py': ('http://docs.python.org/3', None)
+}

webencodings/__init__.py

@@ -41,11 +41,11 @@ def ascii_lower(string):
     This is used for `ASCII case-insensitive
     <http://encoding.spec.whatwg.org/#ascii-case-insensitive>`_
     matching of encoding labels.
-    The same matching is also used, among others,
+    The same matching is also used, among other things,
     for `CSS keywords <http://dev.w3.org/csswg/css-values/#keywords>`_.
 
-    This is different from just using :meth:`unicode.lower`
-    which will also affect non-ASCII characters,
+    This is different from the :meth:`~py:str.lower` method of Unicode strings
+    which also affect non-ASCII characters,
     sometimes mapping them into the ASCII range:
 
         >>> keyword = u'Bac\N{KELVIN SIGN}ground'