Plugin details modal:

* Scroll all content, rather than the dual-pane scrolling awkwardness.
* Better align the header image and title overlay with the display on WordPress.org, at least at full-width.
* Move the close button outside of the modal itself, rather than overlay on top of colors we can't predict.

props stephdau, tellyworth, helen. fixes #27440.

Built from https://develop.svn.wordpress.org/trunk@29474


git-svn-id: http://core.svn.wordpress.org/trunk@29252 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/js/plugin-install.js

@@ -17,7 +17,7 @@ jQuery( document ).ready( function( $ ) {
 			});
 			if ( typeof document.body.style.maxWidth !== 'undefined' ) {
 				tbWindow.css({
-					'top': ( ( 792 < width ) ? 30 : 10 ) + 'px',
+					'top': '30px',
 					'margin-top': '0'
 				});
 			}