Removed scene.lua
Removed old control properties
Property 'collides' depends on property 'visible'

Because the hitbox uses it ¬¬
New helper: unique

Generates an unique version of the given string
New helper: get

Gets something from an element
New trigger: collision

Checks who is colliding
Collision trigger only activates on collided element
Merge branch 'IDgenerator-helper' into dev