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_date.h

@@ -0,0 +1,128 @@
+/* -*- 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_DATE_H_
+#define _QWT_DATE_H_
+
+#include "qwt_global.h"
+#include <qdatetime.h>
+
+/*!
+  \brief A collection of methods around date/time values
+
+  Qt offers convenient classes for dealing with date/time values,
+  but Qwt uses coordinate systems that are based on doubles.
+  QwtDate offers methods to translate from QDateTime to double and v.v.
+
+  A double is interpreted as the number of milliseconds since
+  1970-01-01T00:00:00 Universal Coordinated Time - also known
+  as "The Epoch".
+
+  While the range of the Julian day in Qt4 is limited to [0, MAX_INT],
+  Qt5 stores it as qint64 offering a huge range of valid dates.
+  As the significance of a double is below this ( assuming a
+  fraction of 52 bits ) the translation is not
+  bijective with rounding errors for dates very far from Epoch.
+  For a resolution of 1 ms those start to happen for dates above the
+  year 144683.
+
+  An axis for a date/time interval is expected to be aligned
+  and divided in time/date units like seconds, minutes, ...
+  QwtDate offers several algorithms that are needed to
+  calculate these axes.
+
+  \sa QwtDateScaleEngine, QwtDateScaleDraw, QDate, QTime
+*/
+class QWT_EXPORT QwtDate
+{
+public:
+    /*!
+       How to identify the first week of year differs between
+       countries.
+     */
+    enum Week0Type
+    {
+        /*!
+           According to ISO 8601 the first week of a year is defined
+           as "the week with the year's first Thursday in it".
+
+           FirstThursday corresponds to the numbering that is
+           implemented in QDate::weekNumber().
+        */
+        FirstThursday,
+
+        /*!
+            "The week with January 1.1 in it."
+
+            In the U.S. this definition is more common than
+            FirstThursday.
+        */
+        FirstDay
+    };
+
+    /*!
+      Classification of an time interval
+
+      Time intervals needs to be classified to decide how to
+      align and divide it.
+     */
+    enum IntervalType
+    {
+        //! The interval is related to milliseconds
+        Millisecond,
+
+        //! The interval is related to seconds
+        Second,
+
+        //! The interval is related to minutes
+        Minute,
+
+        //! The interval is related to hours
+        Hour,
+
+        //! The interval is related to days
+        Day,
+
+        //! The interval is related to weeks
+        Week,
+
+        //! The interval is related to months
+        Month,
+
+        //! The interval is related to years
+        Year
+    };
+
+    enum
+    {
+        //! The Julian day of "The Epoch"
+        JulianDayForEpoch = 2440588
+    };
+
+    static QDate minDate();
+    static QDate maxDate();
+
+    static QDateTime toDateTime( double value,
+        Qt::TimeSpec = Qt::UTC );
+
+    static double toDouble( const QDateTime & );
+
+    static QDateTime ceil( const QDateTime &, IntervalType );
+    static QDateTime floor( const QDateTime &, IntervalType );
+
+    static QDate dateOfWeek0( int year, Week0Type );
+    static int weekNumber( const QDate &, Week0Type );
+
+    static int utcOffset( const QDateTime & );
+
+    static QString toString( const QDateTime &,
+        const QString & format, Week0Type );
+};
+
+#endif