Interrupted release upgrade, how to sort out left-over old packages?

[Chris Green]

I think I know now the cause of my 'left-over' PHP5 packages in a
16.04 installation.  (See previous thread)

The system in question got interrupted (the cat walked across the
keyboard!) while doing a do-release-upgrade.  I restarted it and after
a couple of 'apt-get update' and an 'apt-get dist-upgrade' it seemed
to have sorted itself out and have 16.04 properly installed.

However, obviously not all the packages that should have been upgraded
were upgraded, hence my left-over PHP5 packages.  

I've sorted out the PHP5 ones now but I suspect there may be other
left-over packages from 15.10 that haven't been updated.  Is there any
way I can check and update them?

-- 
Chris Green