Refactor the time delays into constants and mention the units

ui/media/js/utils.js

@@ -273,4 +273,10 @@ function BraceExpander() {
         return evaluated(dctParse);
     }
 
-}
+}
+
+function asyncDelay(timeout) {
+    return new Promise(function(resolve, reject) {
+        setTimeout(resolve, timeout, true)
+    })
+}