Add ItemInitializer.lua
Fixed test fail in BuletRepository
Add call ItemInitializer in EnemySpriteCollisionListener
Fixed y offset of item in itemInitializer
insert initialized item sprite to ITemREpository
add ItemRepository
Implemented ItemRepository
Remove items in GameDestroyer
set internal group of BulletRepository and ItemREpository to nil when being destroyed
Add physicsbody to item
Tempolary fix creating item in collision listener
Implement test 'should fly item'
Fixed fail tests
add ItemHitFloorListener
implemented ItemHitFloorListener
set isMovable to item when hit floor
add ITemRoller
add ItemRoller to runtime enterframe listener
fixed indicator in ItemRoller