Fixed footer SNS button and display style adjustment

【Contents of the fix】
■Fixed a bug that the SNS buttons that have been increased for smartphones are not displayed in PC and tablet environments.
■Adjustments to optimize the OGP function.
■Adjusted the display animation and style of the page top button for smartphones.
■Adjusted the display style of the comment heading link on the article detail page.
■Fixed the bug that the circular dot of the slider becomes oval in IE11 environment.

The following files have been modified for this update.
【Fixed files】
footer.php
functions/ogp.php
js/jscript_mobile.js
js/jscript_mobile2.js
languages/en.po
mobile/style-mobile2.css
style-pc.css
style.css
【Added files】
img/common/no_image_blog.gif

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