Hover a thumbnail at its bottom part and move the mouse horizontally to view the actual screenshots from the video
当前为 2020-02-25 提交的版本，查看 最新版本。
这些是此脚本变更过代码的版本。 显示所有版本。
actually downsize overflowing pics
avoid clipping overflow
catch up with the new site layout
show correct sb for updated thumbnail
fix re-activation if didn't start on this thumb last time
dim the area only on hover
left-align preview + show progress
also show on suggestions + don't limit preview size
ignore YT:not-interested when hovering
scale the thumbnail to 200px
switch to inner API
