Build system changed to Cmake, ORM changed to QxORM, Qt6 compatibility.

shop/shop.cpp

@@ -3,7 +3,6 @@
 #include "shopform.h"
 #include "shopservice.h"
 #include "settings/shopsettingsform.h"
-#include "shop-odb.hxx"
 #include "shopoverview.h"
 
 Shop::Shop()
@@ -27,9 +26,9 @@ QWidget *Shop::ui()
 {
     QWidget *uiWidget = IPlugin::ui();
 
-    if (uiWidget == NULL)
+    if (uiWidget == nullptr)
     {
-        return NULL;
+        return nullptr;
     }
 
     qobject_cast<ShopForm*>(uiWidget)->setupForm();