Image by layers is not shown correctly

```
From zxg1127:
> 
> hello，i find some problem about java-psd-library project,may be there are 
bugs.
>
> when i run PsdDemo and load a psd file, the Original image tab show correct 
result,but the Image by layers tab show the wrong result,i think that the 
layers order is wrong.
```

Original issue reported on code.google.com by `boris.su...@gmail.com` on 29 Nov 2010 at 10:10
