kangax/fabric.js — pull request #1720 by asturur (2014-10-01 22:26:40+00:00)
Title: preserve Aspect Ratio for images support

This is draft of implementation of preserveAspectRatio attribute support for images, started to fix issue #384
Basically it can be:
Do not respect aspect ratio
Respect aspect ratio shrinking image to fit (meet)
Respect aspect ratio cutting the image. (slice)
The image cut is not ready yet ( don't know how to do know, some clipping required )

those are the specs:
http://www.w3.org/TR/SVG/coords.html#PreserveAspectRatioAttribute

This is how it should look:
![image](https://cloud.githubusercontent.com/assets/1194048/4429185/2f09068a-45de-11e4-8483-cdc63b9e55b0.png)

I made the image transparent to show rectangles under it for reference.
This is how it looks as of now:
![image](https://cloud.githubusercontent.com/assets/1194048/4429173/d61e97e2-45dd-11e4-960d-f6ad9b33fdba.png)

this is how browser renders it, not good:
![image](https://cloud.githubusercontent.com/assets/1194048/4429183/17619bb4-45de-11e4-9e6e-b74adf3d5399.png)

this is the svg i crafted to show the example:
```xml

```