Clean prefix of annotation assistant, in case a menu item is chosen

Change-Id: Ic770e707e06ad743dea2f70dd8904d21eb50774f
diff --git a/dev/js/src/hint/input.js b/dev/js/src/hint/input.js
index 7145919..adb74b6 100644
--- a/dev/js/src/hint/input.js
+++ b/dev/js/src/hint/input.js
@@ -58,6 +58,14 @@
 
 
   /**
+     * Reset the input value
+   */
+  reset : function () {
+    this._element.value = "";
+  },
+
+
+  /**
    * Update the mirror content.
    */
   update : function () {