TODO

Game features

resizing grid
load/save file
set cell state
yank/paste/clear region
set speed
status line showing:
- iteration
- speed

Render features

make render a separate class
options for live/dead cell characters
zoom/viewport settings
show density

Bin features

use Thor in bin/nlife
manual setting
- grid size
- delay
- input file

UI features

add more controls
speed control
scroll
mouse support
draw/clear/yank/paste tool