Hey there, as I needed the package for myself, I've just packed it with pkg-php-tools and uploaded it to GitHub (1).
Unfortunately I'm no debian maintainer, so I can't upload it to the official repos, but maybe one of the "Debian PHP PEAR Maintainers" can help me? I'll read the docs on how to become a maintainer, but I think this will need some time ... - Alex [1] https://github.com/alehaa/Silex/releases/tag/debian%2F2.0.4-1