Changed firing to trigger by clicking mouse

-Fire is now triggered by clicking mouse, not f
-Holding the mouse button down will only fire one bullet
Fixed explosions triggered by bullets

Chages for Tiles:
-Added DeleteDeadTiles() which deletes all Tiles that has benn killed
with Kill)()
-Every time a Tile is dead, Kill() is called on it instead of it being
deleted directly.
-After the Tiles are destroyed, DeleteDeadTiles() is called. This goes
for explopsions, Ball hit and Bullet hit.

Chages for Bullets:
-Added DeleteDeadBullets() see above.
-Every time a Bullet is dead, Kill() is called on it instead of adding
it to a list of iterators.
-DeleteDeadBullets() now called at the end of UpdateBullets()
-UpdateBullets() has been cleaned up
	-Uses for ( auto p : list ) instead of the long version.
	-Removed vector of iterators with dead bullets.
	-Uses the TileIntersction code in Rect instead of having the
	full algorithm in the loop

TODO:
-Send Bullet fire to oponent
Updated Bullet fire code

-Second bulled is now fire at the right end of the Paddle minus the
width of the bullet. This means that no Bullet is fired outside the
Paddle
-Moved firing of Bullet to spearate function, FireBullet()
SuperBall now also applies to bullet

-If SuperBall is actve, Bullets are not killed when intersection with a
Tile
-Otherwise the Bullet is killed. And the Tile is destroyed if it's a
regular Tile or a hard tile with 1 hit left
Removed IsDestroyed()

-Changed Hit() to set isAlive when decreasing hitsLeft.
-Removed all calls to IsDestroyed() in GameManager and replaced them
with !IsAlive()
-Removed the method from Tile.h
Bullets can now spawn BonusBoxes

-Added new AddBonusBox() that takes
	-Owner as Player
	-Direction as Vector2f
	-Position as Vector2f
	-Tiles destoyed as int32_t
-The old AddBonusBox() which takes a Ball, is now redirected to the new
AddBonusBox()
-UpdateBullets() now calls the new AddBonusBox() to spawn BonusBoxes
Make Bullet use the Speed variable

-Bullet now uses GetSpeed() to calculate new position.
-Bullet now sets speed in constructor