Define the Sprite API

[ThaisRobba]

Ideally, a sprite should offer the following options:

• Anchor/Pivot
• Masking
• Crop
• Scale
• Rotation
• Transform
• Animation
• Event listeners.

[ThaisRobba]

Right now it offers only spritesheet animation through an easy API. I think I might postpone this for v0.3 as it is quite a bit of work to add the others in a clear, concise manner.