Added Sound Controller & audio assets.
Added explosion FX
minor changes
SpriteAnimator - bug correction
minor tweak
Added events for mobile

Explosion, Shoot.
Mobile class : added explosion event
EnemyAI can now limit the number of enemies
Unity scene changed
minor tweaks on explosions
Simplified SpriteAnimator.Play()

No longer needs parameters.
Changed HP type to int (instead of uint)

This was causing a bug in the ship's HP, instead of going down at 0, it
would roll back to uint.maxValue, making the ship invincible.
minor tweak
minor tweak