Fixed multiple bugs / WP5.0 compatible

【Features added and fixed】
■Added support for WordPress 5.0 (Gutenberg).
■Fixed a bug that the slider video may not play in Chrome.
 ※Due to a fix for a change in Chrome’s video playback policy, the video will be played muted.
■Fixed an issue where some thumbnails would appear missing when “Slide” was selected as the hover effect.
■Fixed an issue where images would be trimmed to a different size when selecting the image slider in the header content, even if the recommended size image was registered, resulting in poor quality.
■Fixed an issue where the “Transparency of the color over the image” on the fixed page could not be set to “0”.
■Fixed a display collapse when setting ads on both the “left” and “right” sides of Ad 2 on the article detail page.
■Fixed a bug where the link was stretched to the right margin of the header logo image.
■Added some wording to theme options.

The following files have been modified for this update.
【Corrected files】
admin/inc/basic.php
functions/head.php
functions/page_cf2.php
functions/short_code.php
js/slick.min.js
language/ja.mo
language/ja.po
pagebuilder/pagebuilder.php
pagebuilder/assets/admin/css/admin.css
pagebuilder/assets/admin/js/admin.js
pagebuilder/assets/admin/js/googlemap.js
pagebuilder/assets/css/googlemap.css
pagebuilder/assets/css/pagebuilder.css
pagebuilder/assets/css/simple_table.css
pagebuilder/assets/css/slider.css
pagebuilder/assets/js/googlemap.js
pagebuilder/modules/catchcopy.php
pagebuilder/modules/googlemap.php
pagebuilder/modules/headline.php
pagebuilder/modules/image.php
pagebuilder/modules/simple_table.php
pagebuilder/modules/slider.php
pagebuilder/modules/tab.php
template_parts/index_slider.php
functions.php
style.css