bug#18048: 24.3.92; [patch] eldoc improvements

[Stefan Monnier]

> I didn't find in help-fns.el, but in help.el I found
> `help-function-arglist' which is used by eldoc.

Hmm... no, this one does something different, so it definitely shouldn't
skip &key and other CLisms.

I installed a completely different patch in eldoc which uses
help-make-usage so that the appearance is "as good as C-h f".
This gives us "always upcase" arguments already, so there's no need to
upcase them manually afterwards.

So I also removed support for eldoc-argument-case, which is kind of
a pain to implement properly.

I also installed your &key handling patch, thanks.


        Stefan