scores+restart button done. new moving platform

1)the three best highscores are displayed now when reaching the finish
as well as your own
if you made it into the top three, yours will be colored yellow
resized and -positioned respawn button

2) press R to respawn at the last checkpoint or at the end of the level
to restart the whole layout

3) added another moving platform called movingPlatform which moves up
and down using Sine
maybe replace the violet platforms with the new ones?
-pros: much smoother movement
-cons: a new platform object is needed for each different type of
movement or the distance travelled