Add the ability to set a translate="no" property on any element that
uses the common properties attributes. This also adds the ability to
set rules in the <info> element to select types of elements that should
not be translated. Non-translated text does not appear in PO files and
is not seen by translators, but is included verbatim in the final
translated output document.

The current use case for this is to prevent the PGP keys from being
translated, which makes no sense and introduces duplication.

This work was made possible with assistance by Shaun McCance at the 2017
Open Help Conference.

Sponsored by: iXsystems