DM-384 and DM-242, we disabled the periods-to-underscores translations for new tables ("version 1") but left it in place for old tables ("version 0"). In addition, when reading a table without a version number, we assumed it was version 0, to maintain backwards compatibility.
I think we should modify this slightly: we should assume a table without a version number is version 0 if and only if it also has the AFW_TYPE key. Otherwise we should assume it is version 1. This will allow us to load externally-produced tables without turning any underscores they contain into periods, while still maintaining backwards compatibility with older tables written by afw.