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/doc/man/man3/QwtSystemClock.3

@@ -0,0 +1,86 @@
+.TH "QwtSystemClock" 3 "Mon Jun 1 2020" "Version 6.1.5" "Qwt User's Guide" \" -*- nroff -*-
+.ad l
+.nh
+.SH NAME
+QwtSystemClock \- \fBQwtSystemClock\fP provides high resolution clock time functions\&.  
+
+.SH SYNOPSIS
+.br
+.PP
+.PP
+\fC#include <qwt_system_clock\&.h>\fP
+.SS "Public Member Functions"
+
+.in +1c
+.ti -1c
+.RI "\fBQwtSystemClock\fP ()"
+.br
+.RI "Constructs a null clock object\&. "
+.ti -1c
+.RI "virtual \fB~QwtSystemClock\fP ()"
+.br
+.RI "Destructor\&. "
+.ti -1c
+.RI "bool \fBisNull\fP () const"
+.br
+.ti -1c
+.RI "void \fBstart\fP ()"
+.br
+.ti -1c
+.RI "double \fBrestart\fP ()"
+.br
+.ti -1c
+.RI "double \fBelapsed\fP () const"
+.br
+.in -1c
+.SH "Detailed Description"
+.PP 
+\fBQwtSystemClock\fP provides high resolution clock time functions\&. 
+
+Sometimes the resolution offered by QTime ( millisecond ) is not accurate enough for implementing time measurements ( f\&.e\&. sampling )\&. \fBQwtSystemClock\fP offers a subset of the QTime functionality using higher resolution timers ( if possible )\&.
+.PP
+Precision and time intervals are multiples of milliseconds (ms)\&.
+.PP
+( \fBQwtSystemClock\fP is obsolete since Qt 4\&.8 as QElapsedTimer offers the same precision )
+.PP
+\fBNote\fP
+.RS 4
+The implementation uses high-resolution performance counter on Windows, mach_absolute_time() on the Mac or POSIX timers on other systems\&. If none is available it falls back on QTimer\&. 
+.RE
+.PP
+
+.SH "Member Function Documentation"
+.PP 
+.SS "double QwtSystemClock::elapsed () const"
+
+.PP
+\fBReturns\fP
+.RS 4
+Number of milliseconds that have elapsed since the last time \fBstart()\fP or \fBrestart()\fP was called or 0\&.0 for null clocks\&. 
+.RE
+.PP
+
+.SS "bool QwtSystemClock::isNull () const"
+
+.PP
+\fBReturns\fP
+.RS 4
+true if the clock has never been started\&. 
+.RE
+.PP
+
+.SS "double QwtSystemClock::restart ()"
+Set the start time to the current time 
+.PP
+\fBReturns\fP
+.RS 4
+Time, that is elapsed since the previous start time\&. 
+.RE
+.PP
+
+.SS "void QwtSystemClock::start ()"
+Sets the start time to the current time\&. 
+
+.SH "Author"
+.PP 
+Generated automatically by Doxygen for Qwt User's Guide from the source code\&.