update-manager does not automatically replace packages on a conflict with a virtual package

[Steve Langasek]

libgphoto2 recently had an soname transition; libgphoto2-2 was replaced by libgphoto2-6, libgphoto2-port0 was replaced by libgphoto2-port10.

Update-manager would not automatically replace libgphoto2-port0 with libgphoto2-port10, which is required because:

Package: libgphoto2-port0
Replaces: libgphoto2port
Provides: libgphoto2port
Conflicts: libgphoto2port

Package: libgphoto2-port10
Replaces: libgphoto2port
Provides: libgphoto2port
Conflicts: libgphoto2port

So this is a clear conflicts with the package, which update-manager should handle.

It happens that the conflicts here is also wrong and buggy and should be removed, but u-m should still be able to transparently handle Conflicts with a virtual package without throwing the user to the "partial upgrade" dialog.