put .RESBigEditorPop button in wiki back to its place

the big editor toggler button in wiki page was pushed farther
down after the recent `overflow: visible;` change to
`.wiki-page > .content`. i don't understand why it did that and why
the `.pageactions` (wiki tabbar) which is on the same level as the
big editor button and also has the same `float: right;` rule didn't get
pushed down too?