Feature - Multiply Blend Image Transformer

This feature allows supports configurable image transformer to overlay a multiplier color on an image. The effect intended to replicate this feature in Photoshop.

http://www.photoshopessentials.com/photo-editing/layer-blend-modes/multiply/

The logic is based on this demo: 

http://www.java2s.com/Code/Java/2D-Graphics-GUI/BlendCompositeDemo.htm

The effect is to take an image such as:

![transformergreyscale](https://cloud.githubusercontent.com/assets/6520270/3622777/fe0410de-0e3d-11e4-8730-a14c80e4ac6a.jpg)

And apply a color (00b3b4) overlay:

![transformermultiply](https://cloud.githubusercontent.com/assets/6520270/3622788/4f349a14-0e3e-11e4-91e2-4e47f5383395.jpg)

Additionally you can modify the alpha (transparency intensity) and change the effect (half of previous alpha):

![halftransformermultiply](https://cloud.githubusercontent.com/assets/6520270/3622789/83d8b958-0e3e-11e4-97c7-7113fefbecc0.jpg)