Add get `getDirtyCount` method

src/editor/index.js

@@ -486,6 +486,15 @@ module.exports = config => {
       return c.el;
     },
 
+    /**
+     * Return the count of changes made to the content and not yet stored.
+     * This count resets at any `store()`
+     * @return {number}
+     */
+    getDirtyCount() {
+      return em.getDirtyCount();
+    },
+
     /**
      * Update editor dimensions and refresh data useful for positioning of tools
      *

src/editor/model/Editor.js

@@ -467,6 +467,15 @@ module.exports = Backbone.Model.extend({
     return device && width && !preview ? `(${condition}: ${width})` : '';
   },
 
+  /**
+   * Return the count of changes made to the content and not yet stored.
+   * This count resets at any `store()`
+   * @return {number}
+   */
+  getDirtyCount() {
+    return this.get('changesCount');
+  },
+
   /**
    * Set/get data from the HTMLElement
    * @param  {HTMLElement} el