Add a filter for wp_editor() settings.

props DH-Shredder, JPry, DrewAPicture.
fixes #24472.
Built from https://develop.svn.wordpress.org/trunk@28944


git-svn-id: http://core.svn.wordpress.org/trunk@28741 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Use correct variable.

props azaozz.
see #24472.
Built from https://develop.svn.wordpress.org/trunk@28945


git-svn-id: http://core.svn.wordpress.org/trunk@28742 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Display a correct preview link for drafts when permalinks are disabled.

see #28350.
Built from https://develop.svn.wordpress.org/trunk@28946


git-svn-id: http://core.svn.wordpress.org/trunk@28743 1a063a9b-81f0-0310-95a4-ce76da25c4cd