[Users] Compile 3.8.1 under xubuntu 12.04

[seelenhirt]

> > 
> > No package 'gtk+-2.0' found
> > 
> > The GTK engines 2.20-2 engines are installed. I do not see a
> > development module for GTK in Synaptic.
> >   
> According to this:
> https://launchpad.net/ubuntu/precise/+source/gtk+2.0/ the package
> should be there and have the name libgtk2.0-dev

"sudo apt-get build-dep claws-mail" should install everything you neet
to build claws.