imperfect fix for CJK punct

[pyrocat101]

Quick fix for CJK punctuation typesetting.

[pyrocat101]

若我能够找到中文标点的Unicode区间并把它们标记为中文字符的话，我会更新这个pull request。

[pyrocat101]

从xeCJK的源码来看，Unicode U+2423并不属于CJK字符类的范围内：

\xeCJKDeclareCharClass { CJK }
  {
    "1100 -> "11FF ,
    "2E80 -> "2EFF ,
    "2F00 -> "2FDF ,
    "2FF0 -> "2FFF ,
    "3000 -> "303F ,
    "3040 -> "309F ,
    "30A0 -> "30FF ,
    "3100 -> "312F ,
    "3130 -> "318F ,
    "3190 -> "319F ,
    "31A0 -> "31BF ,
    "31C0 -> "31EF ,
    "31F0 -> "31FF ,
    "3200 -> "32FF ,
    "3300 -> "33FF ,
    "3400 -> "4DBF ,
    "4DC0 -> "4DFF ,
    "4E00 -> "9FFF ,
    "A000 -> "A48F ,
    "A490 -> "A4CF ,
    "A960 -> "A97F ,
    "AC00 -> "D7AF ,
    "B000 -> "B0FF ,
    "D7B0 -> "D7FF ,
    "F900 -> "FAFF ,
    "FE30 -> "FE4F ,
    "FF00 -> "FFEF ,
    "20000 -> "2A6DF ,
    "2A700 -> "2B73F ,
    "2B740 -> "2B81F ,
    "2F800 -> "2FA1F ,
  }

自行定义CJK字符类是否有必要？

[aifreedom]

Hmm.. 也许是XeCJK更新了? 我认为可以把这个自定义mapping暂时设为optional的. 你觉得呢?