Added OGP setting function and fixed display problems on smartphones

【Contents of fixes and feature additions】
■Added OGP setting function to theme options (Facebook/Twitter)
■Fixed the method of specifying the header logo display size in smartphone display.

The following are the files that have been modified for this update.
【Modified files】
admin/theme-options.php
functions.php
header.php
languages/ja.mo
languages/ja.po
mobile/style-mobile.css
style.css

The following files have been added for this update.
【Added files】
functions/ogp.php

For more information, please visit the download site for purchasers of SWEETY (tcd029).