Simplify Sprite API

[BikeLinc]

Make drawing sprites as simple as possible from the public API standpoint.

Look at other engines sprite API's.

[BikeLinc]

[BikeLinc]

Thinking about sprite constructors, the ones I am going to implement now are the following:

• [ ] Sprite( Texture texture, Transform transform )
• [ ] Sprite( Texture texture, int width, int height, Transform )