Autoremove can touch packages, that are assumed to be present
for post-install step.
A good example is dkms, which is dropped in
install.d, but dkms element try to use it in post-install step.
This results in the following log [1]
[1] http://paste.openstack.org/show/797809/
Change-Id: I635af230c6b250fee273039935cf19506e83b3d1
