Introducing Site Icon, favicon management for WordPress.

This v1 marries Jetpack's Site Icon module with the Media Modal, reusing code
from the Custom Header admin. For now, the core-provided icons will be limited
to a favicon, an iOS app icon, and a Windows tile icon, leaving `.ico` support
and additional icons to plugins to add.

Props obenland, tyxla, flixos90, jancbeck, markjaquith, scruffian.
See #16434.



git-svn-id: https://develop.svn.wordpress.org/trunk@32994 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/wp-admin.css

@@ -10,4 +10,5 @@
 @import url(about.css);
 @import url(nav-menus.css);
 @import url(widgets.css);
+@import url(site-icon.css);
 @import url(l10n.css);