Merge pull request #49 from DQNEO/feature/skel_to_english

Squashed commit of the following:

commit f03fbabdad7f858e842e7ccf10433969618da351
Author: DQNEO <DQNEO@dqneo.jp>
Date:   Fri Mar 23 22:31:13 2012 +0900

    translate japanse comments into english