Custom painters for eye and dot #224
Description
It would be nice to have custom painters to generate fancy pics.
I imagine, QrImageView could accept functions like dataModluePainter and eyePainter besides dataModuleStyle and eyeStyle.
The functions would be responsible for rendering a single element (slingle eye, single dot).
For example, eyePainter would get position (top-left, top-right, bottom-left), size, x and y.
dataModluePainter would get size, x, y and information about neighbouring dots (8 dots around), so that the shape could be different if it connects with other dots.