Quicktags: move focusing the editor after inserting content to the end of the code blocks. Fixes a bug in Chrome where both the textarea and the window may auto-scroll to unexpected position on clicking a Quicktags button. Part props avryl, fixes #29944 for trunk.
Built from https://develop.svn.wordpress.org/trunk@29884


git-svn-id: http://core.svn.wordpress.org/trunk@29640 1a063a9b-81f0-0310-95a4-ce76da25c4cd