[FIX] *: use html_translate for non-sanitized html fields

Commit c21568e1 deactivated the sanitization of frontend html fields so
that their modification through the editor worked again. However,
this broke the possibility to display their traduction and to modify
them.

The problem is that the translate option of html fields should not
equal "True" but instead be the html_translate function defined in
openerp.tool.translate. The translate=True option is automatically
change in html_translate though but there is a condition: the field
should be sanitized, which is why this broke since the sanitization
is disabled.

This commit sets the translate option of non-sanitized html fields
to html_translate. Maybe we should investigate for this to be automatic
for non-sanitized html fields as well.

Thanks to @rco-odoo.