add ability to disable child monitor

Author: Graham Butler

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@author.io/element-base",
-  "version": "1.1.2",
+  "version": "1.1.3",
   "description": "Base class for all author-* custom elements (web components).",
   "main": "dist/author-base.min.js",
   "scripts": {

src/element.js

@@ -907,6 +907,20 @@ const AuthorBaseElement = superClass => class extends superClass {
         }
       },
 
+      /**
+       * @method disableChildMonitor
+       * Disable monitoring of child elements.
+       * Disconnects MutationObserver and sets this.childMonitor to null.
+       */
+      disableChildMonitor: {
+        value: () => {
+          if (this.childMonitor) {
+            this.childMonitor.disconnect()
+            this.childMonitor = null
+          }
+        }
+      },
+
       /**
        * @method registerListener
        * Applies an event listener. This listener will be automatically cleaned up