refs #312 navigation bars, contributes also to #347

* allow to set/unset frameless mode in CDockWidget
* adjusted context menus
* adjusted style sheets
* ini settings for margins
* hidden info area to host floating widgets only visible when floating (allows to CDockInfoArea widgets)
* made some private slots non-virtual

src/blackgui/components/invisibleinfoareacomponent.cpp

@@ -0,0 +1,66 @@
+/* Copyright (C) 2015
+ * swift project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "invisibleinfoareacomponent.h"
+#include "ui_invisibleinfoareacomponent.h"
+#include "blackmisc/icons.h"
+
+using namespace BlackGui;
+using namespace BlackMisc;
+
+namespace BlackGui
+{
+    namespace Components
+    {
+
+        CInvisibleInfoAreaComponent::CInvisibleInfoAreaComponent(QWidget *parent) :
+            CInfoArea(parent),
+            ui(new Ui::CInvisibleInfoAreaComponent)
+        {
+            ui->setupUi(this);
+            this->ui->comp_Navigator->allowStatusBar(false);
+            this->initInfoArea();
+        }
+
+        CInvisibleInfoAreaComponent::~CInvisibleInfoAreaComponent()
+        { }
+
+        QSize CInvisibleInfoAreaComponent::getPreferredSizeWhenFloating(int areaIndex) const
+        {
+            InfoArea area = static_cast<InfoArea>(areaIndex);
+            switch (area)
+            {
+            case InfoAreaHorizontalNavigator:
+                return QSize(400, 50);
+            case InfoAreaVerticalNavigator:
+                return QSize(50, 400);
+            default:
+                return QSize(0, 0);
+            }
+        }
+
+        const QPixmap &CInvisibleInfoAreaComponent::indexToPixmap(int areaIndex) const
+        {
+            InfoArea area = static_cast<InfoArea>(areaIndex);
+            switch (area)
+            {
+            case InfoAreaHorizontalNavigator:
+            case InfoAreaVerticalNavigator:
+            default:
+                return CIcons::empty();
+            }
+        }
+
+        void CInvisibleInfoAreaComponent::toggleNavigator()
+        {
+            this->ui->comp_Navigator->toggleFloating();
+        }
+
+    } // ns
+} // ns