Fixed: Aria2 download issue

Fixed the problem that Aria2 could not download images after v1.3.4 update.
The new download url has to be used with cookies, so Aria2 wouldn't work. But 'GM_cookie' couldn't get those cookies with 'httpOnly: true' option, so Aria2 couldn't get full cookies to download via the new download url.
Anyway I tweak it to use old 'large url' to download via Aria2. The final images downloaded are the same with different download urls.

2 tweaks: Hide setting button & New download url for pictures

1. Added function: Able to hide setting button on page. Go change the setting in the setting panel.
2. Changed: New download url for pictures.

Fixed: Will not download video cover when not enabling this feature

Fixed the issue that it still download video covers even when not enabling this feature.

Changed single image download icon color

Changed the single image download icon more clear with different color.

Added function: download images without watermarks

Able to download images without watermarks now. But you need to enable it in settings.
Images quality would be lower than those with watermarks.

Fixed: Download large size of video cover image

It might download the smaller sized video cover image in previous version. Now it's fixed.

Added function: download video cover image

Now it's able to download video cover images while downloading videos.
You could disable this function in the settings.
The naming rule of video cover images is the same with file names for the other images and videos.

Fixed: Able to download on search page

Fixed the problem which it does not work at s.weibo.com.

Fixed: Last modified time of files in the ZIP files in local timezone

Now the last modified time of files in the ZIP files are local datetime.

Optimization: better quality for video

Optimized the way to parse video URLs for better quality from Weibo TV.