Made step to remove ASyncWindow in favour of usage of Future and FutureWatcher.

This should allow concurrency in the plugins to be independent from their container.

Contains also some work on the system for registering plugins.

pglab/QueryTab.h

@@ -8,8 +8,9 @@
 #include "tuplesresultwidget.h"
 
 #include <QWidget>
-#include "PluginContentWidget.h"
+#include "plugin_support/PluginContentWidget.h"
 #include <memory>
+#include "plugin_support/PluginModule.h"
 
 namespace Ui {
 	class QueryTab;
@@ -110,4 +111,14 @@ private slots:
 	void startConnect();
 };
 
+class QueryToolModule: public PluginModule {
+	Q_OBJECT
+public:
+	using PluginModule::PluginModule;
+
+	void init();
+private slots:
+	void new_triggered();
+};
+
 #endif // QUERYTAB_H