first attempt to make About window

ui/widgets/about.cpp

@@ -0,0 +1,29 @@
+// Squawk messenger. 
+// Copyright (C) 2019  Yury Gubich <blue@macaw.me>
+// 
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+// 
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+// 
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "about.h"
+#include "ui_about.h"
+
+About::About(QWidget* parent):
+    QWidget(parent),
+    m_ui(new Ui::About)
+{
+    m_ui->setupUi(this);
+    m_ui->versionValue->setText(QApplication::applicationVersion());
+    setWindowFlag(Qt::Tool);
+}
+
+About::~About() = default;