Expose user's settings and defaults inline

This improves performance by removing two AJAX calls and a lot of
JavaScript promises.

UI/Templates/PreferencesUI/UIxJSONPreferences.wox

@@ -0,0 +1,12 @@
+<?xml version='1.0' standalone='yes'?>
+<container
+    xmlns="http://www.w3.org/1999/xhtml"
+    xmlns:var="http://www.skyrix.com/od/binding"
+    xmlns:const="http://www.skyrix.com/od/constant">
+  <script id="UserDefaults" type="text/json">
+    <var:string value="jsonDefaults" const:escapeHTML="NO"/>
+  </script>
+  <script id="UserSettings" type="text/json">
+    <var:string value="jsonSettings" const:escapeHTML="NO"/>
+  </script>
+</container>