Added experimentalDecorators flag

src/compiler/commandLineParser.ts

@@ -188,10 +188,16 @@ module ts {
             type: "boolean",
             description: Diagnostics.Watch_input_files,
         },
+        {
+            name: "experimentalDecorators",
+            type: "boolean",
+            description: Diagnostics.Enables_experimental_support_for_ES7_decorators
+        },
         {
             name: "emitDecoratorMetadata",
             type: "boolean",
-            experimental: true
+            experimental: true,
+            description: Diagnostics.Enables_experimental_support_for_emitting_type_metadata_for_decorators
         }
     ];