Add old defaults for boxplot to classic style

Author: jenshnielsen

lib/matplotlib/mpl-data/stylelib/classic.mplstyle

@@ -348,6 +348,10 @@ boxplot.meanprops.color: r
 boxplot.meanprops.linestyle: -
 boxplot.meanprops.linewidth: 1.0
 boxplot.medianprops.color: r
+boxplot.meanprops.marker: s
+boxplot.meanprops.markerfacecolor: r
+boxplot.meanprops.markeredgecolor: k
+boxplot.meanprops.markersize: 6.0
 boxplot.medianprops.linestyle: -
 boxplot.medianprops.linewidth: 1.0
 boxplot.notch: False
@@ -503,4 +507,4 @@ animation.convert_path: convert   # Path to ImageMagick's convert binary.
 animation.convert_args:
 animation.html: none
 
-_internal.classic_mode: True
+_internal.classic_mode: True