Cleaned up oauth code based on feedback. Created FlowThreeLegged and OAuthCredentials classes.
diff --git a/httplib2/iri2uri.py b/httplib2/iri2uri.py
new file mode 100644
index 0000000..70667ed
--- /dev/null
+++ b/httplib2/iri2uri.py
@@ -0,0 +1,110 @@
+"""
+iri2uri
+
+Converts an IRI to a URI.
+
+"""
+__author__ = "Joe Gregorio (joe@bitworking.org)"
+__copyright__ = "Copyright 2006, Joe Gregorio"
+__contributors__ = []
+__version__ = "1.0.0"
+__license__ = "MIT"
+__history__ = """
+"""
+
+import urlparse
+
+
+# Convert an IRI to a URI following the rules in RFC 3987
+# 
+# The characters we need to enocde and escape are defined in the spec:
+#
+# iprivate =  %xE000-F8FF / %xF0000-FFFFD / %x100000-10FFFD
+# ucschar = %xA0-D7FF / %xF900-FDCF / %xFDF0-FFEF
+#         / %x10000-1FFFD / %x20000-2FFFD / %x30000-3FFFD
+#         / %x40000-4FFFD / %x50000-5FFFD / %x60000-6FFFD
+#         / %x70000-7FFFD / %x80000-8FFFD / %x90000-9FFFD
+#         / %xA0000-AFFFD / %xB0000-BFFFD / %xC0000-CFFFD
+#         / %xD0000-DFFFD / %xE1000-EFFFD
+
+escape_range = [
+   (0xA0, 0xD7FF ),
+   (0xE000, 0xF8FF ),
+   (0xF900, 0xFDCF ),
+   (0xFDF0, 0xFFEF),
+   (0x10000, 0x1FFFD ),
+   (0x20000, 0x2FFFD ),
+   (0x30000, 0x3FFFD),
+   (0x40000, 0x4FFFD ),
+   (0x50000, 0x5FFFD ),
+   (0x60000, 0x6FFFD),
+   (0x70000, 0x7FFFD ),
+   (0x80000, 0x8FFFD ),
+   (0x90000, 0x9FFFD),
+   (0xA0000, 0xAFFFD ),
+   (0xB0000, 0xBFFFD ),
+   (0xC0000, 0xCFFFD),
+   (0xD0000, 0xDFFFD ),
+   (0xE1000, 0xEFFFD),
+   (0xF0000, 0xFFFFD ),
+   (0x100000, 0x10FFFD)
+]
+ 
+def encode(c):
+    retval = c
+    i = ord(c)
+    for low, high in escape_range:
+        if i < low:
+            break
+        if i >= low and i <= high:
+            retval = "".join(["%%%2X" % ord(o) for o in c.encode('utf-8')])
+            break
+    return retval
+
+
+def iri2uri(uri):
+    """Convert an IRI to a URI. Note that IRIs must be 
+    passed in a unicode strings. That is, do not utf-8 encode
+    the IRI before passing it into the function.""" 
+    if isinstance(uri ,unicode):
+        (scheme, authority, path, query, fragment) = urlparse.urlsplit(uri)
+        authority = authority.encode('idna')
+        # For each character in 'ucschar' or 'iprivate'
+        #  1. encode as utf-8
+        #  2. then %-encode each octet of that utf-8 
+        uri = urlparse.urlunsplit((scheme, authority, path, query, fragment))
+        uri = "".join([encode(c) for c in uri])
+    return uri
+        
+if __name__ == "__main__":
+    import unittest
+
+    class Test(unittest.TestCase):
+
+        def test_uris(self):
+            """Test that URIs are invariant under the transformation."""
+            invariant = [ 
+                u"ftp://ftp.is.co.za/rfc/rfc1808.txt",
+                u"http://www.ietf.org/rfc/rfc2396.txt",
+                u"ldap://[2001:db8::7]/c=GB?objectClass?one",
+                u"mailto:John.Doe@example.com",
+                u"news:comp.infosystems.www.servers.unix",
+                u"tel:+1-816-555-1212",
+                u"telnet://192.0.2.16:80/",
+                u"urn:oasis:names:specification:docbook:dtd:xml:4.1.2" ]
+            for uri in invariant:
+                self.assertEqual(uri, iri2uri(uri))
+            
+        def test_iri(self):
+            """ Test that the right type of escaping is done for each part of the URI."""
+            self.assertEqual("http://xn--o3h.com/%E2%98%84", iri2uri(u"http://\N{COMET}.com/\N{COMET}"))
+            self.assertEqual("http://bitworking.org/?fred=%E2%98%84", iri2uri(u"http://bitworking.org/?fred=\N{COMET}"))
+            self.assertEqual("http://bitworking.org/#%E2%98%84", iri2uri(u"http://bitworking.org/#\N{COMET}"))
+            self.assertEqual("#%E2%98%84", iri2uri(u"#\N{COMET}"))
+            self.assertEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}"))
+            self.assertEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}")))
+            self.assertNotEqual("/fred?bar=%E2%98%9A#%E2%98%84", iri2uri(u"/fred?bar=\N{BLACK LEFT POINTING INDEX}#\N{COMET}".encode('utf-8')))
+
+    unittest.main()
+
+