implement entire project in nodes

Project items are now represented directly in nodes opening up more versatility and possibilities. This is the first iteration of this and will be buggy. Need to test thoroughly.

app/dialog/preferences/tabs/preferencesbehaviortab.h

@@ -23,17 +23,17 @@
 
 #include <QTreeWidget>
 
-#include "preferencestab.h"
+#include "dialog/configbase/configdialogbase.h"
 
 namespace olive {
 
-class PreferencesBehaviorTab : public PreferencesTab
+class PreferencesBehaviorTab : public ConfigDialogBaseTab
 {
   Q_OBJECT
 public:
   PreferencesBehaviorTab();
 
-  virtual void Accept() override;
+  virtual void Accept(MultiUndoCommand* command) override;
 
 private:
   QTreeWidgetItem *AddParent(const QString& text, const QString &tooltip, QTreeWidgetItem *parent = nullptr);