Add item to the list of limitations that points out the lack of support
for authenticated proxies.  This is noted elsewhere, but this makes it
easier to find.

Fix typo where it was already mentioned.

This closes SourceForge bug #110619.
diff --git a/Doc/lib/liburllib.tex b/Doc/lib/liburllib.tex
index 1cdfafd..3901a9c 100644
--- a/Doc/lib/liburllib.tex
+++ b/Doc/lib/liburllib.tex
@@ -63,7 +63,7 @@
 see the \function{urlencode()} function below.
 
 The \function{urlopen()} function works transparently with proxies
-whicd do not require authentication.  In a \UNIX{} or Windows
+which do not require authentication.  In a \UNIX{} or Windows
 environment, set the \envvar{http_proxy}, \envvar{ftp_proxy} or
 \envvar{gopher_proxy} environment variables to a URL that identifies
 the proxy server before starting the Python interpreter.  For example
@@ -262,6 +262,10 @@
 the module \refmodule{htmllib}\refstmodindex{htmllib} to parse it.
 
 \item
+This module does not support the use of proxies which require
+authentication.  This may be implemented in the future.
+
+\item
 Although the \module{urllib} module contains (undocumented) routines
 to parse and unparse URL strings, the recommended interface for URL
 manipulation is in module \refmodule{urlparse}\refstmodindex{urlparse}.