Fixed multiple bugs

【Fixed content】
■Fixes to the explanatory images in the theme options.
■Fixed a bug that the video does not play when “Video” is set as the header content of the top page (Mac/Safari).

The following are the files that have been modified for this update.
【Corrected files】
admin/img/page_link_type1.jpg
admin/img/page_link_type2.jpg
functions/head.php
header.php
style.css

【Deleted files】
js/jquery.vide.js
js/jquery.vide.min.js