Automattic/_s — pull request #419 by kovshenin (2014-02-27 19:30:49+00:00)
Title: Add HTML5 support for WordPress galleries.

See: https://core.trac.wordpress.org/changeset/27302

Also a note: trailing commas with multiple-line arrays is a good idea and has a purpose. Trailing commas in inline array definitions doesn't have any benefits and looks weird :)