Single data type definition for Academic_Institution

[cuihtlauac]

Use the same type in ocamlorg and ood for Academic_Institution, without duplicate definitions

• It's defined in src/ocamorg_data/data_intf.ml
• src/ocamlorg_data defines two libraries
  • Data_intf, which is used both by ood and ocamlorg
  • Data, which is only used by ocamlorg but includes Data_intf
• Should have no impact on ocamlorg source or behaviour (no file touched)
• Removes code in tool/ood-gen/lib/academic_institution.ml
• Type definition is moved from data.mli into data_intf.mli, like in the intf hack, except it's compiled.