Japanese help file on Windows

[Bastian M. <bma...@we...>]

Hi,

Currently the CHM windows help file in Japanese is encoded in SHIFT-JIS. 
Since the English version is using UTF-8 on the other hand, this should 
also be fine for the Japanese variant. I would appreciate feedback, if 
the wgnuplot-ja-utf8.chm file on SF in the testing/ directory also works 
fine for others.

   Bastian