Gnuplot 5.4.10 release (fixes build regressions in 5.4.9)

[Ethan A M. <me...@uw...>]

I have placed a release tarball of 5.4.10 on SourceForge

    sourceforge.net/projects/gnuplot/files/gnuplot/5.4.10/gnuplot-5.4.10.tar.gz

The 5.4.10 patchlevel release repairs a regression in 5.4.9 that caused
a build failure in the postscript terminal if neither cairo nor libgd
support was configured.

This is probably the final update to version 5.4,
as a full release of version 6 is expected by the end of this year.

Changes in 5.4.10
=================
* FIX    postscript: build failed in 5.4.9 if neither gd nor cairo libraries present
* FIX    data-dependent variable point properties in polar plots
* FIX    configure script modified to work with macOS+Homebrew
* CHANGE use 64-bit integers for iteration (allows iteration over dates)

    Ethan