Switch to $strings (i.e. `string.Template` instances) for all i18n substitutions
Original LP Author: Sumana Harihareswara , LP Link: https://bugs.launchpad.net/bugs/1414156
Switch to $strings (i.e. string.Template
instances) for all i18n substitutions. We should be able to mechanically update all existing translations.
From http://wiki.mailman.psf.io/DEV/Mailman%203.0?action=diff&rev2=30&rev1=28 -- a TODO for the Mailman 3.x series.