[Vimoutliner] Heading colorization problem with doublebyte characters

[apparit at inter7.jp]

Thank you for reply,

> Just to make sure it really has to do with Japanese 2 byte characters, could 
> you please try it with regular ascii and see if the symptom goes away? If it 
> does, we need to troubleshoot the character set. If it doesn't, there's 
> something else we need to troubleshoot.

With regular ASCII characters, I could not reproduce the symptom.

As far as I tested, putting one or more ASCII characters at tha head of each heading 
appears to prevent VO-colors from showing incorrect levels,
even if the following characters of the heading are all Japanese ones.

Character sets I used for Japanese characters were EUC-JP and Shift_JIS,
and both seem to show this symptom.