watch out for check entries in menus

We have a lot of menu entries that are checkable. They have checkboxes
in them or they have radio buttons. Some of the these entries are a
little broken in that they can have check marks in them but they are not
marked as truly "checkable". 

If a menu entry is broken the symptoms are that, if you have a theme
that draws a blank box for unchecked entries and a tick mark for checked
entries, then when the state is "unchecked" you get a menu entry without
the "unchecked" box but when its "checked" you get a menu entry with a
check mark. The inconsistency from non-broken entries is annoying

I fixed a pile of these over the w/e, but if anyone sees any more then
let me know. Its hardly a critical bug, but they're easy to fix and
polish the UI experience a bit.

C.