footer declared in the site.xml is not inherited in multi-module sites

attaching a site.xml descriptor to a parent pom, while the body.head element is inherited from children, body.footer is not.

Quoting Lukas from dev@ ML,

A quick look at the source code shows that the footer is not taken care of in doxia-decoration-model's DefaultDecorationModelInheritanceAssembler. The footer was only introduced in the last doxia release and this was apparently overlooked.