Added values for target dots

Added value and setable color to target dot. If the snake eats the dot,
it will enlarge for the value of the dot.
Fixed bug in mulitplayer when colliding head to head. New winstate draw
Fixed bug in single- and multiplayer. The snake dies when some strange
control glitches appear.
Improved performance. Removed the large array of dots and replaced it
with a continuous growing arraylist on the snake. replaced x and y with
dot and fixed movement issues with a Direction enum instead of 4
booleans.