Adding cython v0.20.2 in third-party.

third_party/cython/src/Cython/Tempita/compat3.py

+import sys
+
+__all__ = ['b', 'basestring_', 'bytes', 'next', 'is_unicode']
+
+if sys.version < "3":
+    b = bytes = str
+    basestring_ = basestring
+else:
+
+    def b(s):
+        if isinstance(s, str):
+            return s.encode('latin1')
+        return bytes(s)
+    basestring_ = (bytes, str)
+    bytes = bytes
+text = str
+
+if sys.version < "3":
+
+    def next(obj):
+        return obj.next()
+else:
+    next = next
+
+if sys.version < "3":
+
+    def is_unicode(obj):
+        return isinstance(obj, unicode)
+else:
+
+    def is_unicode(obj):
+        return isinstance(obj, str)
+
+
+def coerce_text(v):
+    if not isinstance(v, basestring_):
+        if sys.version < "3":
+            attr = '__unicode__'
+        else:
+            attr = '__str__'
+        if hasattr(v, attr):
+            return unicode(v)
+        else:
+            return bytes(v)
+    return v