Add devsite-compatible lang ids to whitelist and add a redirect for the old uppercase ids.

Change-Id: I1fada8710a43a9ac8d3d2d12a53023e78d686513

scripts/app_engine_server/memcache_zipserve.py

@@ -110,7 +110,7 @@ class MemcachedZipHandler(webapp.RequestHandler):
   REDIRECT_TYPE_TEMP = 'temporary'  # Redirect 'type'string indicate a 302
                                     #   Redirect should be served
   intlString = 'intl/'
-  validLangs = ['en', 'de', 'es', 'fr','it','ja','ko','ru','zh-CN','zh-TW']
+  validLangs = ['en', 'de', 'es', 'fr','it','ja','ko','ru','zh-CN','zh-cn','zh-TW','zh-tw']
 
   def TrueGet(self, reqUri):
     """The top-level entry point to serving requests.

scripts/app_engine_server/redirects.yaml

@@ -543,9 +543,13 @@ redirects:
   type: permanent
   comment: Redirect to new location
 
+- src: /intl/zh-CN/...
+  dst: /intl/zh-cn/...
+  type: permanent
 
-
-
+- src: /intl/zh-TW/...
+  dst: /intl/zh-tw/...
+  type: permanent
 
 # -------------------- EASTER EGG REDIRECTS ----------------------