Sprite initializers should set positions as floats

[einarf]

Curerntly sprite initializers are setting positions etc as integers. This is confusing for the user when the look at the the property values. When the sprite rotates or move the values suddenly change to floats. it could also potentially have a positive effect when sprite buffers are written causing one less cast.

There might be more instances of this in the sprite class.

[DragonMoffon]

This can be closed.