Add quit cli command and app quit option after stream session. Fixes #92 (#138)

* Add quit cli command and app quit option after stream session. Fixes #92

* Code review fixes.

app/cli/quitstream.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <QObject>
+#include <QVariant>
+
+class ComputerManager;
+class NvComputer;
+
+namespace CliQuitStream
+{
+
+class LauncherPrivate;
+
+class Launcher : public QObject
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE_D(m_DPtr, Launcher)
+
+public:
+    explicit Launcher(QString computer, QObject *parent = nullptr);
+    ~Launcher();
+
+    Q_INVOKABLE void execute(ComputerManager *manager);
+    Q_INVOKABLE bool isExecuted() const;
+
+signals:
+    void searchingComputer();
+    void quittingApp();
+    void failed(QString text);
+
+private slots:
+    void onComputerFound(NvComputer *computer);
+    void onComputerSeekTimeout();
+    void onQuitAppCompleted(QVariant error);
+
+private:
+    QScopedPointer<LauncherPrivate> m_DPtr;
+};
+
+}