+ dpkg let packages disappear then they have no files any longer and
+ nothing depends on them. We need to collect this as dpkg as well as
+ APT doesn't know beforehand that the package will disappear, so the
+ only possible option is to tell the user afterwards about it.
+ To enhance the experience we also try to forward the auto-install
+ flag so the disappear-causer(s) are not autoremoved next time -
+ for the transfer to happen the disappeared version needs to depend
+ on the package the flag should be forwarded to and this package
+ needs to declare a Replaces on the disappeared package.
+ \param pkgname Name of the package that disappeared
+ */
+ void handleDisappearAction(string const &pkgname);