Fix accesskey problems

Make sure there are always only one button with given accesskey.
Add accesskeys when editor is shown, remove those accesskeys from
other buttons. Also renamed the classes of save and skip buttons
for docs so that I would not be adding accesskeys to those too,
which would again break things.

Change-Id: I064561bf801f4cad531fc6711d52a8ab446ccaa5
Merge "Fix accesskey problems"