Create Updated ODF 1.1 RNG Schema to accompany Errata 01

OFFICE-3743 leads to changes to the in-line schema for ODF 1.1.

It appears that the schema errors have not led to problems in practice, even though the report of the discrepancy is recent.

The following ODF 1.1 Errata 01 items involve changes to the schema:

OFFICE-3743 section 3.1.18 (missing meta: prefix)

OFFICE-3808 section 14.5.1 (third item), correct placement of <optional>