- add io.ungetc and string.isutf8
- maintain input order in delete-duplicates
- error for unicode escapes greater than 0x10ffff
- make more builtins constant (use setc instead of set)
- use prog1 in begin0 macro
- array-ref was incorrectly called array-ref! in aliases.scm
- use (void) instead of () in 0-arg C functions
- don't do arithmetic with void*
James Turner