This is a combination of 12 commits from master branch:

tdf#92256: ODF save/load syntax for string reference

Related tdf#92256: map CONV_OOO to listbox item no.1

tdf#92256: Introducing CONV_A1_XL_A1 address pseudoconvention

tdf#92256: OOXML save/load syntax for string reference

add unhandled case in switch

that comment is not correct anymore

don't generate invalid XLSX files

tdf#92256: Handle case when string ref syntax is unknown

tdf#92256: Make OOXML filter CONV_A1_XL_A1 aware too

tdf#92256: Make sure ref syntax of Excel docs gets saved

tdf#92256: Save ref syntax when different from native one

tdf#92256: Don't force CalcA1 syntax on all !Microsoft xlsx docs

Change-Id: I226d5644ce729f1311aefc9a8998b3a75633c334
Reviewed-on: https://gerrit.libreoffice.org/17837Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>