Investigate justified layout for panel grid

[eidens]

Flickr and Google Photos use a "justified layout" for images:

• All images in a row have the same height.
• Each row can have a different width.
• Each pair of images has a gap of the same width between them.

This could look very nice for the panel grid. Here are some links:

https://medium.com/google-design/google-photos-45b714dfbed1
https://code.flickr.net/2016/04/05/our-justified-layout-goes-open-source/
https://code.flickr.net/2015/03/24/much-photos/
https://github.com/flickr/justified-layout