Improvements to the plugin information modal:

* Show the banner image when available.
* Show contributors and ratings breakdown in the FYI box.
* Show reviews in a tab.

props stephdau, tellyworth, paulwilde, michalzuber. see #27440. fixes #19784, #22599, #26202.

Built from https://develop.svn.wordpress.org/trunk@29040


git-svn-id: http://core.svn.wordpress.org/trunk@28828 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Autoprefixer for [29040]. see #27440.

Built from https://develop.svn.wordpress.org/trunk@29041


git-svn-id: http://core.svn.wordpress.org/trunk@28829 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Remove an unused JS variable after [29036]. see #27406.

Built from https://develop.svn.wordpress.org/trunk@29042


git-svn-id: http://core.svn.wordpress.org/trunk@28830 1a063a9b-81f0-0310-95a4-ce76da25c4cd