Renew the updater branch

Now with some actual consensus on what the updater will do!

gui/dialogs/UpdateDialog.cpp

@@ -0,0 +1,28 @@
+#include "UpdateDialog.h"
+#include "ui_UpdateDialog.h"
+#include "gui/Platform.h"
+
+UpdateDialog::UpdateDialog(QWidget *parent) : QDialog(parent), ui(new Ui::UpdateDialog)
+{
+	MultiMCPlatform::fixWM_CLASS(this);
+	ui->setupUi(this);
+}
+
+UpdateDialog::~UpdateDialog()
+{
+}
+
+void UpdateDialog::on_btnUpdateLater_clicked()
+{
+	reject();
+}
+
+void UpdateDialog::on_btnUpdateNow_clicked()
+{
+	done(UPDATE_NOW);
+}
+
+void UpdateDialog::on_btnUpdateOnExit_clicked()
+{
+	done(UPDATE_ONEXIT);
+}