[mew-int 3116] Why is completion-ignore-case buffer-local in draft buffers?

Having completion-ignore-case buffer-local in the draft buffer
interferes with completion in the minibuffer.
But I guess it's needed for code like in mew-complete-address?

Please have a look at http://debbugs.gnu.org/cgi/bugreport.cgi?bug=12615

It's not clear to me if this problem needs to be fixed in emacs or in
mew, but it has been bothering me for quite some time.

- Harald