Log message:
graphics/mypaint-brushes1: import mypaint-brushes1-1.3.1

Brushes used by MyPaint and other software using libmypaint.

This data package is versionned. This are the brushes to be used by
libmypaint 1.x, not the ones to be used by current development version
(libmypaint 2.x; which has no releases to the day of writing).