awful.client.floating.get() does some sensible defaults. E.g. dialogs are
floating by default. Since floating.toggle only checked the property, these
defaults made it break.
So floating.toggle() should use floating.get to decide if a given client is
floating. It should also use "false" instead of "nil" when the client is made
non-floating or else the default will apply again.
Thanks to vsp for making me figure this out. :)
Signed-off-by: Uli Schlachter <psychon@znc.in>