Changes from 1.2 to 1.3: - reverted or/c to union, since we can't rely on or/c being present in all v300 systems. Have to rethink this transition. Changes from 1.1 to 1.2: - Fixed packaging error that omitted contract-utils.ss. Changes from 1.0 to 1.1: - Added version spec to doc.txt, source code - Replaced union contract operator (now deprecated) with or/c - Added license clarification to contract-utils.ss.