Log Message:
Update gnuplot-nox11 to 4.0.0

Closes PR #25450 submitted by me.

Ok'ed wiz@/snj@/root (at) garbled.net

Thanks to xtraeme@ for fixing GD's X11 issues.

>From the CHANGELOG:

 What's New
 ==========

 The list of changes is immense this time, so only the highlights
 can be given here.  For the full details, see the NEWS file or the
 ChangeLog, or look into the online version of the documentation at
 http://www.gnuplot.info/docs/gnuplot.html#What_is_New_in_Version_4.0
 You'll quite probably have to (re-)read large parts of the
 documentation to learn all the details that have changed.

 Major changes visible to users:
 -------------------------------

 o Global Command syntax change: instead of 'set no...' it's now
   'unset ...'.
 o Commands 'set data style', 'set function style' and 'set linestyle'
   changed to 'set style {data|function|line}, respectively.
 o Colour-coded plots in 3D and simulated 2D through the new 'pm3d'
   plotting style.
 o Boxes drawn by plotstyles 'boxes', 'candlesticks' and boxed errorbar
   styles can be filled with solid colors or hatch patterns.
 o New plot style 'with filledcurves' to fill an area defined by a curve
   in solid colour.
 o Windows, X11, OS/2 and GGI interactive graphical terminals now support
   interaction with the plot window by mouse and hotkeys.
 o The "enhanced" mode has been generalized from PostScript to some
   other terminal drivers.
 o 'set hidden3d' mode accepts non-grid data and hides them behind gridded
   surfaces plotted with them.
 o Several new terminal drivers: EMF, PDF, SVG, GGI, epslatex, aqua.
 o New function to query if a user-defined variable exists.
 o PNG and JPEG terminals using the GD library support libfreetype to
   use true-type fonts.
 o 'set label' can output a point symbol the comment refers to, and the
   text itself can be rotated by arbitrary angles (on some terminals).
 o The color of text elements can be changed.
 o 'set size ratio' now affects 3D plots, too.
 o The 'dgrid3d' can be switched between thin-plate splines and
   the older weighted averaging method, at compile time.
 o Some terminals now support 'koi8-r', ISO-Latin-2 and CP-852
   encoding of user input.
 o Windows gnuplot recognizes the Unix/X11 style '-persist' option,
   and supports changing linewidth by core gnuplot commands.
 o A native compilation option of gnuplot for Mac OS X is now part of
   the mainline source, using the 'aquaterm' driver [3].
 o Datafile comment character, column separator and decimal sign
   can be changed.
 o Arrows can be drawn with relative coordinates for the head, and the
   heads can be filled.
 o Allows 'set timefmt' independantly for each axis, and supports new
   '%s' format for seconds-since-1970 input.
 o Even more documentation misprints have been fixed, thanks to
   Shigeharu TAKENO

 Internal changes:
 -----------------

 o Reorganization of the entire source tree.
 o Broken into considerably more source files than before.
 o Large sets of related global variables have been collected into
   relatively few global data structures (the 'axis' array and a
   global 'key' data structure, e.g.).
 o The gnuplot_x11 driver no longer is installed in the PATH, to
   avoid confusion about it.
 o Scaling and ticking of time/date axes respects the fact that
   12 and 60 are not the same 10 or 100 much better.

 And, obviously, more bug fixes than could possibly fit into this
 narrow margin...