Migrate from OldTextTemplate to NewTextTemplate of Genshi
Genshi is officially in transition since 2007 to a new syntax for TextTemplate.
The standard TextTemplate is still (today) the OldTextTemplate (it does not seem it will change any time soon) but in order to prepare to an hypothetical removal, we could prepare the migration.
We need to provide a tool that convert from the old syntax to the new one. This tools will be used by the modules to migrate the template in the __register__
method.
Or the migration could be done in two steps by storing with the template the syntax version used. So we can use the proper class to render it. And later if the old syntax is removed we make the migration.