Jean i18n work

Instrumented source code so that `i18ndude` can rebuild the `.pot` file properly.

    # Rebuild `cmfplomino.pot`
    $ ./bin/i18ndude rebuild-pot \
            --pot src/Products.CMFPlomino/Products/CMFPlomino/i18n/cmfplomino.pot \
            --create CMFPlomino \
            --merge src/Products.CMFPlomino/Products/CMFPlomino/i18n/manual.pot \
            src/Products.CMFPlomino/Products/CMFPlomino/

    # Update all the `cmfplomino-LANG.pot` files
    $ find src/Products.CMFPlomino/Products/CMFPlomino/ \
            -name "*.po" -not -name "*plone*" \
            | xargs ./bin/i18ndude sync \
                --pot src/Products.CMFPlomino/Products/CMFPlomino/i18n/cmfplomino.pot