Implement separate mailman subcommands for add, delete and sync members.

Mark Sapirorequested to merge
msapiro/mailman:fix_686 into master

Fixes #686 (closed)

This adds three new mailman subcommands: addmembers, delmembers and syncmembers with more controls and functions than the similar mailman members options.

It still needs tests and a NEWS item.

Edited by Mark Sapiro

Merge request reports