installer needs to check for Sophos

[jdreed]

If you install Sophos on Linux, it will helpfully block "suspicious" file accesses, if a file gets opened too frequently. Like, say, something in /var/cache/openafs.

We should check for the presence of it and refuse to install Debathena until it is configured correctly. It's also possible we should divert openafs' init script and refuse to run, which is presumably better than hanging. One of the OLC students is investigating precisely what is needed.