inconsistency between char-numeric? and digit-value

[Takashi Kato]

digit-value should return number if char-numeric? returned #t so this should not be the case

(char-numeric? #\xb2)
;; -> #f
(digit-value #\xb2)
;; -> 2

[Takashi Kato]

Handling special case of unicode numbers (Fixes #120)

→ <<cset 59c6d659c251>>