[scribus] pdf compression

[Cezary Grabski]

> Feel free to apply the patch to your own copy of the source code. In my
> eyes, the patch is not complete enough and does not cover enough of the
> cases we would want to cover in a stable branch, plus it has not had
> enough testing. I updated the bug to that effect yesterday.

I had provide this patch as example how this feature can be achieved, but it 
has big limitation only to jpg files, as I afraid touch other kind of image 
files because of its additional features like alpha channels.
Someone with larger knowledge about image processing should get my patch and 
complete it.
But for me it is quite suitable, because 99% images I use is in jpg format.
cezaryece