Implement About Button Functionality (#3005)

src/citra_qt/aboutdialog.cpp

@@ -0,0 +1,19 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "aboutdialog.h"
+#include "common/scm_rev.h"
+#include "ui_aboutdialog.h"
+
+AboutDialog::AboutDialog(QWidget* parent)
+    : QDialog(parent, Qt::WindowTitleHint | Qt::WindowCloseButtonHint | Qt::WindowSystemMenuHint),
+      ui(new Ui::AboutDialog) {
+    ui->setupUi(this);
+    ui->labelBuildInfo->setText(ui->labelBuildInfo->text().arg(
+        Common::g_build_name, Common::g_scm_branch, Common::g_scm_desc));
+}
+
+AboutDialog::~AboutDialog() {
+    delete ui;
+}