Added game icon
Added depth field to Mobile

Depth (int) is used to determine which layer a mobile should occupies on
screen.
Default is :
- Ships are on depth 0, projectiles on depth -1
- Game : depth 10 (the maximum depth)

the camera is at depth -1
Added keyboard listener to EventHorizon

The keyboard listener triggers an event when a key is pressed :

- Escape : exit application.

Also, removed mobiles list.
Updated game icon
Added earth background.

Because it looks super nice.
Collisions are now triggers.
Added MobileData struct

This stores the mobile's game information, like Hit points,
isDestroyable.
Added EnemyShip Testaros
Pools now create game objects.
Mobile prefabs don't store colliders and scripts.
SetModel() no longer instantiates gameobject.
Ship class no longer stores HitPoints.

The struct MobileData does it.
Projectile class no longer stores damage.

MobileData does it.
Unity settings modified
Modified graphics

Added trail, explosion, changed some folders.
Projectiles now create effects on impact

For now, explosion.
Pool now create decals
minor changes
Enemy Ship is no longer abstract.
Gun now shoots pool instantiated projectiles