Qt5 built in qwt (#570)

- qt4->qt5
- in built qt5 6.1.5 because rhel7 is not upto date with qt5, removed findqwt.cmake
- made a fix in qwt lib (qwt_plot_layout.h) to work with 5.15 and lower versions for qrect constr.
- qt5 forms fixed, qt4 many hard coding forms switched to forms including qtabwidget, scrolls etc, fonts moved to forms
 - docking option enabled by default, removed option to disable docking feature from "Mode"
- added qVersionResolve utility functions to handle compatibility before and after qt5.12
- qtplots (ian's code) takes in gain mode enable to set some settings within the class, with proper gain plot ticks
- ensure gain plots have no zooming of z axis in 2d and y axis in 1d
- removed placeholder text in qpalette in main window form as its not supportd until 5.12 (so using qt5.9 designer insted of qt5.15 to cope)
- tab order
Servers:
- fixed some error messages that were empty for fail in funcs (mostly minor as if this error, major issues)

libs/qwt-6.1.5/include/qwt_plot_dict.h

@@ -0,0 +1,58 @@
+/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
+ * Qwt Widget Library
+ * Copyright (C) 1997   Josef Wilgen
+ * Copyright (C) 2002   Uwe Rathmann
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the Qwt License, Version 1.0
+ *****************************************************************************/
+
+/*! \file !*/
+#ifndef QWT_PLOT_DICT
+#define QWT_PLOT_DICT
+
+#include "qwt_global.h"
+#include "qwt_plot_item.h"
+#include <qlist.h>
+
+/// \var typedef QList< QwtPlotItem *> QwtPlotItemList
+/// \brief See QT 4.x assistant documentation for QList
+typedef QList<QwtPlotItem *> QwtPlotItemList;
+typedef QList<QwtPlotItem *>::ConstIterator QwtPlotItemIterator;
+
+/*!
+  \brief A dictionary for plot items
+
+  QwtPlotDict organizes plot items in increasing z-order.
+  If autoDelete() is enabled, all attached items will be deleted
+  in the destructor of the dictionary.
+  QwtPlotDict can be used to get access to all QwtPlotItem items - or all
+  items of a specific type -  that are currently on the plot.
+
+  \sa QwtPlotItem::attach(), QwtPlotItem::detach(), QwtPlotItem::z()
+*/
+class QWT_EXPORT QwtPlotDict
+{
+public:
+    explicit QwtPlotDict();
+    virtual ~QwtPlotDict();
+
+    void setAutoDelete( bool );
+    bool autoDelete() const;
+
+    const QwtPlotItemList& itemList() const;
+    QwtPlotItemList itemList( int rtti ) const;
+
+    void detachItems( int rtti = QwtPlotItem::Rtti_PlotItem,
+        bool autoDelete = true );
+
+protected:
+    void insertItem( QwtPlotItem * );
+    void removeItem( QwtPlotItem * );
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif