* etc/schema/od-schema-v1.2-os.rnc: OASIS standard
* etc/schema/od-manifest-schema-v1.2-os.rnc: OASIS standard
* etc/schema/schemas.xml: Fix uri to rnc files.
* lisp/org-odt.el (org-export-odt-schema-dir): Modified to
accommodate change in rnc file names.
* contrib/lisp/org-e-odt.el (org-e-odt-schema-dir): Modified
to accommodate change in rnc file names.