Partial fix to #648142, from Timo Lindfors.
* Suppress apt-listbugs and apt-listchanges. Michael Prokop.
* Fix parsing of "@" dependencies. Colin Watson. Closes: #667022.
+ * Fix NameError re "f" in restriction parsing.
+ Martin Pitt. Closes: #647882.
Packaging fixes:
* Add Recommends against pbuilder, whose dependency resolver adt-run