Make possible to obtain image parameters

```
It would be very useful to add feature to obtain image parameters (width, 
height, etc).

Currently it's possible to get from buffered image object: 
Thumbnails.of(...).scale(1f).asBufferedImage()

Without .scale(1f) it fails with exception though it's unnecessary operation 
for the case.
```

Original issue reported on code.google.com by `x4j...@gmail.com` on 1 Oct 2012 at 11:27
