Wobbliness in host_entries management

[mattock]

In certain so far unknown conditions an empty $host_entries manages to slip into the hosts template, causing a ERB error. This is possibly related to answer files.

[mattock]

We decided to remove the host_entries parameter altogether, as the proper place for the entries is the DNS.

In the long run, though, we want to bring it back, but due to issues in Kafo hash entry itself we'd probably need to write a Ruby function which takes an array of array of strings and converts that into a hash that is passed to the hosts module.