fix for bug 10994 breaks ido customizations in major way

[Le Wang]

bug: http://emacs.1067599.n5.nabble.com/bug-10994-23-3-ido-mode-ido-next-match-ido-prev-match-work-wrong-with-same-elements-td300.html

The committed fix converts equal to eq, causing any plugin that propertizes the completion list to hang Emacs.

This bug is filed as: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=14334

The original bug report is essentially this:

(ido-completing-read "dat is whrong -> " '("2" "3" "3" "3" "4" "5")) 

What's the expected behaviour in this case?  Shouldn't the duplicates from the list just be removed?

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Le