* Merge with Debian unstable; remaining Ubuntu changes: - Build against guile 1.8 instead of 1.6. (forwarded to Debian #493974) - Fix gs-common build dependency to ghostscript. (forwarded to Debian #504569) - Update build dep libltdl3-dev to libltdl7-dev. (forwarded to Debian #504571) * Build against lua 5.1 instead of 5.0. This drops this Debian delta and moves Ubuntu towards the newer lua version, which we need to do at some point anyway.