Release 3.0.0-beta.4

• restore default export for easier migration (CJS is only impacted consumer now) (6ac7c4d)
• better colocation of createCopier (09b3f3e)
• remove unnecessary caching of DataView / ArrayBuffer values (51bc53d)
• code cleanup and better circular management for maps / sets (1656bc0)
• split out copiers from utils, and use more defined copiers for JIT optimizations (c303049)
• code cleanup, and optimize for runtime speed on object clones (b82035e)