- Forked ikkez/f3-schema-builder into lib/db/cortex/schema/ (6 files)
- Integrated FK constraint methods into Schema class
- ConstraintAdapter rewritten as thin backward-compatible facade
- Removed external ikkez/f3-schema-builder dependency
- Fixed 12 multi-DB driver bugs (3 typos: imb->ibm, obdc->odbc;
  4 missing findQuery entries; 4 incomplete introspection methods;
  1 missing space in pgsql query)
- Added IBM DB2 support for hasForeignKey, hasIndex, listIndex, addForeignKey
- Added MSSQL/pgsql support for hasIndex column introspection
- Updated README, changelog, version to 2.0.0
- 513 tests all passing