Properly cache external reference values in named ranges.
Properly cache external reference values in named ranges.

Values of the external references used only in named ranges were
not cached properly.  This commit fixes it.

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core