Rework character icons to display faces

[Calandiel]

Currently, character icons show the same sprite regardless of the person. Instead, we should use 2D paperdolls, like those in Crusader Kings 2 with stacking images for different layers (front hair, back hair, base face, chin, mouth, nose, eyes, iris, back clothes, front clothes, ears, etc).

[Calandiel]

This is almost finished, only pending graphics