Debian folder and deb packages building support in build.xml

The 'deb' target invokes the targets 'deb-32' and 'deb-64', which in turn prepare the debian packages, generate them and clean afterwards. It leaves 4 files in 'resources' folder -- 2 deb packages (i386 and amd64) and their .changes files so they can be picked up later by repository updating scripts.