Bring back the changes to the template XSD file

This issue was created 2020-02-21 in jdvorak001/CERIF-TG-Tools, which is about to be erased. I'm therefore copying the contents here:

@jdvorak001 commented on 21 Feb:
The corrections made in openaire/guidelines-cris-managers#79

@jdvorak001 pushed a commit that referenced this issue on 6 Mar:
@lremy 
(closes #1) change xslt processor
a16bacd
