An implementation of Cowan's game of life.
The game consists of a 20 x 20 grid of cells. Users can left click a
dead cell (denoted by "-" ) to make it alive (denoted by "x").
clicking on a live cell causes nothing. Right clicking on a cell
shows numbers of live neighbor cells for the clicked cell on the
console. Initially all cells are in a dead state. After giving the
seed input by making some cells alive the program displayed next
states for cells when button "Start" is clicked. Button "Clear" can
be clicked to clear the states of cells; to make all of them dead.