Add death freezing + new death animation state + re-activated old animation states

[modelarious]

Player now freezes in place when they die: close #254 Player now has 7 animation states and they are all active again: close #320 close #321

var MCAnimation = {
  WALK: 1,
  JUMP: 2,
  DASH: 3,
  FALLING: 4,
  WALLSLIDE: 5,
  IDLE: 6,
  DEATH:7
};