gui: Add RenderTarget struct, an IPC helper class

gui/rendertarget.cpp

@@ -0,0 +1,14 @@
+#include <QDataStream>
+
+#include "rendertarget.h"
+QDataStream &operator<<(QDataStream &out, const RenderTarget &rc)
+{
+	out << rc.path << rc.page;
+	return out;
+}
+
+QDataStream &operator>>(QDataStream &in, RenderTarget &rc)
+{
+	in >> rc.path >> rc.page;
+	return in;
+}