Python Sudoku AI

Basic Usage:

Mouse:
	left button = select
	right button = de-select

Keyboard:
	N = new empty board
	L = load board from ./puzzle/ folder
	Esc = exit

	D = delete entered number
	0 = delete entered number
	C = show/hide candidate number
	H = get hint(s) (under construction)

	E = eliminate candidate number
	U = run hidden single solver
	V = run naked single solver