OpenFormula: Cleanup of Normative References

In the latest draft we have an Appendix A "References". This appears to be a copy of an the references from ODF 1.0 or ODF 1.1, with some additional references added. We need to clean this up.

1) OASIS template requires the references to be in section 1, as part of the introduction. See ODF 1.2 Part 3, for example.

2) We need to split the references into normative and non-normative references. In other words, does the reference define a requirement? Or is it just background information.

3) It appears that many of the references are not really used. They sould be removed.

4) We should also verify the currency of the remaining references and consistency with the other parts of ODF 1.2. We wouldn't, for example, want to reference two different versions of the Unicode standard between OpenFormula and ODF 1.2 Part 1.