Prep Plugin for release on WordPress.org (#23)

* Update translation text domain
* Escape everything that should be escaped.
* Add nonce checks where needed.
* Sanitize all inputs.
* Apply Code style changes across the codebase.
* Correct many deprecation notices.
* Optimize load order of many filters.
* Add Proper Build script
* Use emojii flags
* Fix i18n deprecation  notice for translating too early
* Put all scripts in footer and load async

assets/js/settings-loader.js

@@ -0,0 +1,13 @@
+settings_loader = wu_block_ui('#wp-ultimo-wizard-body');
+
+/**
+ * Remove the block ui after the settings loaded.
+ *
+ * @since 2.0.0
+ * @return void
+ */
+function remove_block_ui() {
+
+	settings_loader.unblock();
+
+}