Canvas API maintenance (Blend Modes)

[Kevin Rushforth]

Looks good to me, although you will want to change the javadoc comment 
to say "blend mode used for compositing" or similar.

-- Kevin


Joe Andresen wrote:
> In addition to ImageOps... We had decided later on that we would drop the strange behavior of the CompositeOperations in Canvas and simply support the JavaFX BlendModes.
>
> We decided BlendMode was a better name than composite because it is consistent with other JavaFX API.
>
> Trivial Change to the API can be seen below:
>
> import javafx.scene.effect.BlendMode;
>
> ...
>
>    /**
>      * Sets the Global Composite Operation of the current state.
>      * 
>      * @param op
>      */
>     public void setGlobalBlendMode(BlendMode op);
>     
>     /**
>      * Gets the Global Composite Operation of the current state.
>      * 
>      * @return CompositeOperation 
>      */
>     public BlendMode getGlobalBlendMode();
>
> -Joe
>