Fix QTags.closeAllTags(), replace 'tb' with 'ed' in quicktags,js to make it...

Fix QTags.closeAllTags(), replace 'tb' with 'ed' in quicktags,js to make it clear it is the editor instance not the toolbar, small comments quick edit fixes, see #16695, fixes #15911

git-svn-id: https://core.svn.wordpress.org/trunk@18576 1a063a9b-81f0-0310-95a4-ce76da25c4cd