global minor modes and Custom groups

[Dave Love]

I'm reminded of something I meant to propose before.

Since most (?) high-level customization is done through global minor
modes, and navigating through all the Custom options can be hard work,
I think there should be a new Custom group with entries generated
automatically for options defined with `define-minor-mode'.  I don't
know what it should best be called, but I think it should appear at
the top of the M-x customize tree.

This is trivial to implement and I think it could be useful if the
number of such options (around 60) isn't too daunting itself.