Import Mailman 2 translations

Original LP Author: Terri , LP Link: https://bugs.launchpad.net/bugs/1158466

Many of the options and help text from Mailman 2 are similar to those used in Mailman 3. We need someone to export the mailman 3 strings and figure out how many of them can re-use translations from Mailman 2 to jump-start our translation efforts.