Folders "Brushes", "Palette" and "Palette/Custom" now get created if they don't exist (tested on Windows export).
Also, the palettes don't need the Default palette to work anymore, and Default along with bubblegum16 aren't copied to the Palette folder now.
They're like File brushes, but each time you draw, expect to see something different!
To make a random brush, just put the images you want in the same folder (under the main Brushes folder of course), and make sure their filename starts with "%".
I also changed _process() to _input() in Canvas.gd, so there may be some unexpected behavior.
