Media Library feature is very helpfull to manage images/videos.
That’s will be awesome
Where is it? Did they made a new release with that? 
There’s no option for this ATM.
As a work around you can create a draft page and use that as a “media libary” by copy pasting those images in other pages. But: first, this doesn’t work for feature images, and second, testing images (especially for feature images) are still accessible on the server.
I’m used to try out multiple images before launching the final version of a post and I don’t want those images to be accessible by any means. :)
Having an option to clean/purge all those images that are not linked with a post would be awesome.
I know there is ghost-purge-images but I’m using Ghost(Pro) and I can not use that.