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

core/coreplugin.cpp

@@ -16,14 +16,10 @@ CorePlugin::CorePlugin()
     f.close();
 }
 
-CorePlugin::~CorePlugin()
-{
-}
-
 void CorePlugin::initServiceUi()
 {
-    m_service = NULL;
-    m_ui = NULL;
+    m_service = nullptr;
+    m_ui = nullptr;
     m_settingsUi = new GlobalSettingsForm();
 }