Task #562
Updated by Aaron Marcuse-Kubitza about 10 years ago
* put the destination table at the beginning of the mapping, rather than nesting it within a hierarchy of tables it has fkeys to
* requires #561 to be done because autogenerated pkeys require the nested normalization format to be propagated properly
* note that normalized VegCore's @traceable.id_by_source@ now provides an alternate pkey that can be used for duplicate-merging when the referenced table provides enough for a natural key (causing a natural key to be used for @traceable.id@), but the referencing table uses a source-specific numeric key (which is enough for a collision on @traceable.id_by_source@ but not @traceable.id@)