Add the interface for elements, which can bounce
Add interface for elements, from which other can bounce
Add interface for elements, from which other cann't bounce
Add class of collision handler for collision bouncing element with bounced
Add class of collision handler for collision bouncing element with unbounced
Add class of collision handler for collision of unbouncing elements
Add class for ball
Add class for brick
Add class for destroyable brick
Add class for undestroyable brick
Add class for racket
Add class for swarm element
Add class for swarm
small mistake
Merge pull request #3 from LepilkinaElena/master

End model package