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_widget_overlay.h

@@ -0,0 +1,148 @@
+/* -*- 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
+ *****************************************************************************/
+
+#ifndef QWT_WIDGET_OVERLAY_H
+#define QWT_WIDGET_OVERLAY_H
+
+#include "qwt_global.h"
+#include <qwidget.h>
+#include <qregion.h>
+
+class QPainter;
+
+/*!
+   \brief An overlay for a widget
+
+   The main use case of an widget overlay is to avoid
+   heavy repaint operation of the widget below.
+
+   F.e. in combination with the plot canvas an overlay
+   avoid replots as the content of the canvas can be restored from
+   its backing store.
+
+   QwtWidgetOverlay is an abstract base class. Deriving classes are
+   supposed to reimplement the following methods:
+
+   - drawOverlay()
+   - maskHint()
+
+   Internally QwtPlotPicker uses overlays for displaying
+   the rubber band and the tracker text.
+
+   \sa QwtPlotCanvas::BackingStore
+ */
+class QWT_EXPORT QwtWidgetOverlay: public QWidget
+{
+public:
+    /*!
+       \brief Mask mode
+
+       When using masks the widget below gets paint events for
+       the masked regions of the overlay only. Otherwise
+       Qt triggers full repaints. On less powerful hardware
+       ( f.e embedded systems ) - or when using the raster paint
+       engine on a remote desktop - bit blitting is a noticeable
+       operation, that needs to be avoided.
+
+       If and how to mask depends on how expensive the calculation
+       of the mask is and how many pixels can be excluded by the mask.
+
+       The default setting is MaskHint.
+
+       \sa setMaskMode(), maskMode()
+     */
+    enum MaskMode
+    {
+        //! Don't use a mask.
+        NoMask,
+
+        /*!
+           \brief Use maskHint() as mask
+
+           For many situations a fast approximation is good enough
+           and it is not necessary to build a more detailed mask
+           ( f.e the bounding rectangle of a text ).
+         */
+        MaskHint,
+
+        /*!
+           \brief Calculate a mask by checking the alpha values
+
+           Sometimes it is not possible to give a fast approximation
+           and the mask needs to be calculated by drawing the overlay
+           and testing the result.
+
+           When a valid maskHint() is available
+           only pixels inside this approximation are checked.
+         */
+        AlphaMask
+    };
+
+    /*!
+       \brief Render mode
+
+       For calculating the alpha mask the overlay has already
+       been painted to a temporary QImage. Instead of rendering
+       the overlay twice this buffer can be copied for drawing
+       the overlay.
+
+       On graphic systems using the raster paint engine ( QWS, Windows )
+       it means usually copying some memory only. On X11 it results in an
+       expensive operation building a pixmap and for simple overlays
+       it might not be recommended.
+
+       \note The render mode has no effect, when maskMode() != AlphaMask.
+     */
+    enum RenderMode
+    {
+        //! Copy the buffer, when using the raster paint engine.
+        AutoRenderMode,
+
+        //! Always copy the buffer
+        CopyAlphaMask,
+
+        //! Never copy the buffer
+        DrawOverlay
+    };
+
+    QwtWidgetOverlay( QWidget* );
+    virtual ~QwtWidgetOverlay();
+
+    void setMaskMode( MaskMode );
+    MaskMode maskMode() const;
+
+    void setRenderMode( RenderMode );
+    RenderMode renderMode() const;
+
+    void updateOverlay();
+
+    virtual bool eventFilter( QObject *, QEvent *);
+
+protected:
+    virtual void paintEvent( QPaintEvent* event );
+    virtual void resizeEvent( QResizeEvent* event );
+
+    virtual QRegion maskHint() const;
+
+    /*!
+       Draw the widget overlay
+       \param painter Painter
+     */
+    virtual void drawOverlay( QPainter *painter ) const = 0;
+
+private:
+    void updateMask();
+    void draw( QPainter * ) const;
+
+private:
+    class PrivateData;
+    PrivateData *d_data;
+};
+
+#endif