- Update to gnuplot 5.2.3
* NEW "set grid {no}vertical" adds grid lines in the xz and xz planes
* NEW "set cntrparam {firstlinetype N} {{un}sorted}"
* CHANGE drop non-working support for YIQ color space
* CHANGE expand \n characters when printing into a datablock
* CHANGE allow contour plots to opt out of hidden3d processing
* CHANGE special-case code to speed up handling of logscale axes
* CHANGE do not write GPFUN_* variables to "save" output file
* CHANGE default to density 100 for "set fs solid", 50 for "set fs transparent"
* FIX potential buffer overflow in gprintf formats containing %%
* FIX immediate response to ctrl-Z when libreadline is used for input
* FIX warning messages inside a bracketed clause could trigger early exit
* FIX tweak logscale tic range limits and minor tic generation intervals
* FIX stats FOO using 'namedcolumn' name columnhead
* FIX clipping of INRANGE->UNDEFINED line segments
* FIX use of logscale y axis in "set view map" or "set pm3d map" modes
* FIX placement of colorbox in "set view map" mode
* FIX autoscaled axis range of logscale axes in "set view map" mode
* FIX polar mode "with yerrorbars" error bars are radial, not vertical
* FIX clipping of circles whose center is offscreen to the left or bottom
* FIX snap to x=zero for function plot sampling does not apply to logscale x
* FIX canvas terminal: apply both color and alpha channel to points and lines
* FIX svg terminal: apply current color to dots
* FIX qt terminal: include "notitle" plots in accounting for toggle operations
* FIX svg terminal: point plot empty title produced spurious mousing directive
* FIX tikz terminal: failed to recognize dashtype 1

- Update to gnuplot 5.2.2