OFBIZ-8250 and after Deepak at OFBIZ-7942 (too bad I missed that :/) I found that the ignore_missing option of the <#include Freemarker directive does not work. I reported to the Freemarker incubating project.
Hopefully this will be fixed. It will then remove the need of creating empty files for the svn and git info footers when building.
In the meantime I'll provide the change in the themes footers.