Update to sofa 20131202_c

This PR updates ERFA to match the SOFA revision released earlier this month.  

It also updates the version number, so we can go ahead with a 1.1.1 release immediately if this is merged.  Note that such a release would also include the changes in #23 (which were included as-is in the SOFA release, so they don't appear in the diff here).

@sergiopasra - it looks to me like these are entirely bugfix changes, so no changes are needed to ``ERFA_LIB_VERSION_INFO``.  Do you agree?

Also, @sergiopasra and @olebole, as far as you're concerned, is it fine if I just do a 1.1.1 release once this is merged?