Writing vertical bar escaped symbol doesn't emit read invariant value

[Takashi Kato]

Following symbol isn't emit with read invariant value;

'|'
|
;; -> |'\x0a|

[Takashi Kato]

Added ; after hex value of vertical bar escaped symbol (Fixes #53) Modified not to emit vertical bar if the symbol element if more than 0x80

→ <<cset 489c907f4c10>>