Added BonusPickup message

Improved #8

When local player picks up a Bonus Box, a BonusPickup message is sent to
the oponent. Intersections are only tested against local BonusBoxes to
prevent counting a Bonus Box twice

TODO:
-Add more bonues types and add code to differentiate between them
Added possiblity for several bonus types

Fixes #8

-ApplyBonus( ...) will now check for local vs remote player and type of
bonus to apply. To add new bonus effects, simply add a check for it
here.
-Added Death, which takes a single life from the player. If the player
has 1 life, it'll be game over for that player
Fixed issues with Death bonus effect

-Fixed bug caused by Renderer trying to dele an object that doesn't
exist
-All balls are now removed if your lives drops to 0
-Game over text is now 'No more lives' instead of 'No more levels'