Blits a tensor as an image at the location (xpos,ypos) and scaled by the scaling factor . scale is 1 by default if not supplied. (xpos,ypos) is (0,0) by default if not suppled.

If scale is 1 then 1 pixel corresponds to 1 location in a Tensor. If the Tensor is a 2-dimesional m x n then the image would be grey-scale with width m and height n. The elements of the Tensor should be values between 0 and 1. 

	w=gfx.Window();
	x=torch.Tensor(100,50);
	x:zero();
	for i=1,100 do
		x[i][math.floor((i+1)/2)]=1;
	end
	w:blit(x); -- blit grey line on black background

If the Tensor is a 3-dimesional m x n x 3 then the image would be RGB (corresponding to the 3rd dimension) with width m and height n. The elements of the Tensor should be values between 0 and 1. 

	w=gfx.Window();
	x=torch.Tensor(100,50,3);
	x:zero();
	for i=1,100 do
		x[i][math.floor((i+1)/2)][1]=1;
	end
	w:blit(x); -- blit red line on black background