Respects KeepInventory Rule
Lag while open (mostly) fixed. This may cause some synchronization problems. If the backpack doesn't update the fluid tanks visually just take it off and put it on again.
Dupe bug squashed.
Added Czech localization.
Will not dissappear when blowing up now.
Should not dissappear when trying to place where the player has not permissions to.
Fixed effect removals from Bat, Squid, Pigman and Dragon backpack, as well as the way they apply the effects.