Log Message:
gnuplot: Update to 5.4.6

Changelog:
Changes in 5.4.6
================
* NEW    set key {columns <exact no of columns>}
	 set key {keywidth <exact width>}
* NEW    XDG support
	   startup file:      $XDG_CONFIG_HOME/gnuplot/gnuplotrc
	   history file:      $XDG_STATE_HOME/gnuplot_history
	   wxt configuration: $XDG_CONFIG_HOME/gnuplot/gnuplot-wxt.conf
* CHANGE remove "alldoc" build target
* CHANGE plot with polygons fillstyle empty really does mean empty
* FIX    windows: various problems mixing piped input and stdin        Bug #2491
* FIX    x11: bad interactions of lt nodraw, bgnd and dash pattern     Bug #2572
* FIX    wxt: export-to-file widget should preserve line properties
* FIX	 svg: set initial default fill to "none"
* FIX    png: back-compatibility with very old versions of gdlib       Bug #2579
* FIX    variable pointtype, pointsize in plot style yerrorlines
* FIX	 border color for polygons with variable fillcolor
* FIX	 definition followed by iteration in a plot command            Bug #2580
* FIX	 parametric plot with filledcurves y1=<limit>                  Bug #1797