Includes: Developed to get new system working with inline includes

Adds logic for locating and splitting text nodes.
Adds specific classes to offload tag/content specific logic.

app/Util/HtmlDocument.php

@@ -149,4 +149,19 @@ class HtmlDocument
     {
         return $this->document->saveHTML($node);
     }
+
+    /**
+     * Adopt the given nodes into this document.
+     * @param DOMNode[] $nodes
+     * @return DOMNode[]
+     */
+    public function adoptNodes(array $nodes): array
+    {
+        $adopted = [];
+        foreach ($nodes as $node) {
+            $adopted[] = $this->document->importNode($node, true);
+        }
+
+        return $adopted;
+    }
 }