Improve skill button interface :
-The skills cooldown is shown by the number
-The white circle around the skill button shows the duration of the lingering skills effect (for example : DoomTerra' sword) or the chanelling time (for example : Azurath's Blizzard)

-Added sparks effect when DoomTerra successfully reflected an incoming missile.
-Human now have blinking white animation when they got hit.
-Human can bounce around when got hit.