Named Image Transforms - Quality

All Image Quality to be specified per Named Transform

quality values range from: 0 - 100 [ low - original layer quality ]

Transform params are in the format:  `quality:quality=50`

Example quality reduction to "5"

![image_png__640x438_](https://cloud.githubusercontent.com/assets/1451868/4930522/8914ce60-6565-11e4-8122-ccf0d253bf1a.png)

This PR is a different approach on #347