Minor bug fixes and feature additions

【Details of fixes】
■Added custom script function.
■Fixed an error that could appear in the theme options screen.

The following files have been modified for this update.
【Fixed files】
admin/theme-options.php
functions/head.php
languages/ja.mo
languages/ja.po
style.css

For more information, please visit the VIEW(tcd032) download site for purchasers.