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

core/settingsform.cpp

@@ -15,12 +15,12 @@ SettingsForm::SettingsForm(QWidget *parent) :
     ui->setupUi(this);
 
     foreach (IPlugin *plugin, Context::instance().plugins()) {
-        if (plugin->settingsUi() != NULL)
+        if (plugin->settingsUi() != nullptr)
         {
             SettingsService srv(plugin->pluginId());
             IForm *tab = qobject_cast<IForm*>(plugin->settingsUi());
 
-            if (tab != NULL)
+            if (tab != nullptr)
             {
                 tab->loadEntity();
                 ui->tabWidget->addTab(tab, QIcon(), plugin->settingsTabLabel());