A video reference: https://www.youtube.com/watch?v=rGbZf5VDlaY&feature=youtu.be&hd=1

//name:Erika Chao
//date:7/25/2018
//description:Here, I have created a program for the cellTicTacToe class and add three files
//in it that is the gif image files that includes blank.gif, circle.gif and cross.gif.
//Next a line border is set for each of the cell so that the value of boundary is easily visible
// when the use clicks on the cell then the cellTicTacToe would be set so as to put the
//cross or the circle by making a call on to the setContent method of the cell.
//program...