Add timestamp as a default typedInput

and update Inject and change nodes to match,
and add some tests.

red/api/locales/en-US/editor.json

@@ -222,7 +222,8 @@
             "num": "number",
             "re": "regular expression",
             "bool": "boolean",
-            "json": "JSON"
+            "json": "JSON",
+            "date": "timestamp"
         }
     }
 }

red/api/theme.js

@@ -62,7 +62,6 @@ module.exports = {
         }
         themeSettings = null;
         theme = settings.editorTheme;
-
     },
 
     app: function() {

red/runtime/util.js

@@ -182,6 +182,8 @@ function evaluateNodeProperty(value, type, node, msg) {
         return JSON.parse(value);
     } else if (type === 're') {
         return new RegExp(value);
+    } else if (type === 'date') {
+        return Date.now();
     } else if (type === 'msg' && msg) {
         return getMessageProperty(msg,value);
     } else if (type === 'flow' && node) {