Fixing issue5475 : urllib2.getproxies not documented

Doc/library/urllib.rst

@@ -265,6 +265,15 @@ Utility functions
    to decode *path*.
 
 
+.. function:: getproxies()
+
+   This helper function returns a dictionary of scheme to proxy server URL
+   mappings. It scans the environment for variables named ``<scheme>_proxy``
+   for all operating systems first, and when it cannot find it, looks for proxy
+   information from Mac OSX System Configuration for Mac OS X and Windows
+   Systems Registry for Windows.
+
+
 URL Opener objects
 ------------------