Added plugin to automatially create aliases (if they are not existing) a...

This plugin enable a feature to automatically create aliases defined in application.ini.
There are some standard aliases that must always exist and a standard user is not aware of the fact that e.g. postmaster@domain must exist. The alias abuse@domain should exist, if not it is possible that your domain will get into a spam blacklist.
This plugin ensures that also a not skilled user as always the required aliases active.