This modifies the lightbox to only display images inside the
".message_inline_image" class, rather than all images inside the
message body, which currently includes things like the bot icon.
This fixes the styling to stay on the screen of most reasonably sized
monitors along with extending the JavaScript code to allow for the
video to be keyed to in the lightbox.
This adds an image feed that you can scroll through with hotkeys
in the lightbox.
The left and right arrow keys along with the left and right arrows
will go to the prev/next image, and clicking on an image will also
take a user to that image.
Brock Whittaker
Daw-Ran Liou
Tim Abbott