Revisions changes.
 * Eliminates the bloated Revisions meta box in favor of 'Revisions: #' in the publish box.
 * Adds ability to compare autosave to current post, when revisions are disabled.
 * Makes autosaves stand out visually, including "Restore This Autosave".

Also:
 * Adds missing capability check for restoring a revision.
 * When no revision matches the post's current modified time, avoid marking an autosave as 'current'.
 * Fixes wp_get_post_autosave() to return an autosave even when revisions are disabled.
 * Add 'check_enabled' arg to wp_get_post_revisions(); false avoids the wp_revisions_enabled() check.
 * Adds a responsive slider that is narrower for fewer versions. props markjaquith.

see #24804.



git-svn-id: https://core.svn.wordpress.org/trunk@24790 1a063a9b-81f0-0310-95a4-ce76da25c4cd