Fixes bugs:

• REPL showed cache warning. #94
• sint-list->bytevector raised an error if given list contained 0. #97
• RSA decryption didn't restore original value. #98

Improvements:

• Bundled libffi can be used on x64 environment. #93
• Better cooperation of syntax-case and er-macro-transformer. #96
• Performance improvement of JSON parser.
• timer-schedule! and timer-reschedule! procedures can now accept time duration object as period argument.

New features:

• (text json) has been added.
• OAEP padding is supported for RSA encryption/decryption by rsa-oaep-padding procedure.

New documents:

• SRFI-13 convention procedures of (util bytevector) is documented.
• (sagittarius threads) is documented.
• (text sxml html-parser) is documented.

Incompatible changes:

• (scheme base) now doesn't export import. #95