Fix for stasising.

- Removes cloaks from var.STASISED when var.STASISED[cloak] <= 0
- Slight rewrite of fstasis(). The stasis value for a player can now be
  specified directly. If data[1] <= 0, stasis is removed for the
  player if player had one. If data[1] > 0, that amount is set for the
  player's stasis. It now catches ValueError exceptions for invalid values
  of data[1].