Dear maintainers:

I found eww fails to show card-images which is described in the following web page:

For example, if you open following page with eww & firefox, you will notice the differences:   http://www.interdb.jp/pg/pgsql05.html

I modified shr.el a little bit to support "data-src" attribute, so eww can display card-images properly.

 Hope it helps.

Regards

yc