THRIFT-2506 Update TProtocolException error codes to be used consistently throughout the library

Patch: Jens Geyer
diff --git a/lib/hs/src/Thrift/Protocol.hs b/lib/hs/src/Thrift/Protocol.hs
index f3b342a..6068d16 100644
--- a/lib/hs/src/Thrift/Protocol.hs
+++ b/lib/hs/src/Thrift/Protocol.hs
@@ -188,6 +188,8 @@
     | PE_NEGATIVE_SIZE
     | PE_SIZE_LIMIT
     | PE_BAD_VERSION
+    | PE_NOT_IMPLEMENTED
+    | PE_DEPTH_LIMIT
       deriving ( Eq, Show, Typeable )
 
 data ProtocolExn = ProtocolExn ProtocolExnType String