Log Message:
gnuplot: updated to 5.4.10

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)

Changes in 5.4.9

NEW qt: support building with Qt6
CHANGE check plugin version at time of import
FIX prevent segfault if GNUPLOT_DRIVER_DIR is invalid
FIX (regression) only y autoscale yerrorbars to points in xrang
FIX possible memory corruption if clipping causes 0-size polygons
FIX wxt: initialization of key box toggle state
FIX post: handle pixmaps