Chicken Scheme 6.0

Chicken Scheme 6.0 introduces major updates including full R7RS compliance with all small language modules now in the core system, UTF-8 string representation for complete Unicode support, and replacement of blob operations with R7RS-compatible bytevectors. The release also restructures several APIs, moving primitives to appropriate R7RS modules, implementing file-locking with thread-safe flock(2) calls, and changing process operations to return process objects instead of PIDs.