所有功能插件 for WPBakery页面构建器（ formerly Visual Composer） 3.6.7

- Improvement: add alt attribute for all image

- New: Expand Slider, expandable slider with auto delay slideshow, support lightbox, support YouTube, Vimeo video, image etc.

New: Card Carousel, Avatar with lightbox, support YouTube, Vimeo video, image etc (compatible with modern browser only).