Updated the Japanese comment to be more understandable.
bash document Japanese version
just an update of Japanese introduction part
just collected the order of comments and commands of last part
add a contributor line :)
Merge pull request #685 from ahirose/master

[R/ja-JP] [bash/ja-JP][bash/en]Updated the Japanese comment to be more understandable for R, new translation for the bash document, and a small correction of the English bash one.