Enhancement: optionally expose list owners' addresses

[Andrea Brugiolo]

Please note this is not a bug but just a kind enhancement request.

In GNU Mailman version 2.1.24 (I seem) You closed bug #1694384 which, among other things, asked for
not exposing the list administrator(s) personal email address(es) in the page footer.

While I appreciate this new default, in general, in small environment I would find it useful if
users could still individually identify the persons who are directly responsible for a project,
with no harm for their privacy and/or workflow related problems.

Therefore I would like the default behavior could be changed by means of a specific option (global
and/or per list) for exposing the list administrators' addresses instead of the generic list
owner's address.

Would you please consider adding it?

Thank you very much