Add QML folder in project tree, show files there

Use the full path for folders to sort in the project tree.

For virtual folders ensure that the path ensures the sorting we want.

Reviewed-By: kkoehne

src/plugins/projectexplorer/projectnodes.cpp

@@ -558,11 +558,6 @@ bool ProjectNode::sortNodesByPath(Node *n1, Node *n2) {
     return n1->path() < n2->path();
 }
 
-bool ProjectNode::sortFolderNodesByName(FolderNode *f1, FolderNode *f2)
-{
-    return f1->displayName() < f2->displayName();
-}
-
 /*!
   \class SessionNode
 */