The files are supposed to be downloaded in a privileged location
that the user can't access. If the user wipes the data of the
application, the updates downloaded are not removed. Perform a
one-time cleanup so that our downloads dir doesn't grow without
control.
INCOMPLETE is used for any update that isn't verified, even if the
file has been completed. This change is mostly needed to support
imported downloads, which we take as complete, but unverified.
Compare the previously downloaded updates list with the current one
and check if the old list includes all the updates of the new list.
If the network is not available at the time of the check, a new
check is scheduled.
Gabriele M