Prevent ido-cr+ from using old ido-ubiq as fallback

When upgrading, "ido-cr+-fallback-function" would get set to the
"completing-read-ido" function from the old version of ido-ubiquitous,
which would result in infinite recursion. This commit prevents ido-cr+
from using the old ido-ubiquitous functions.

ido-completing-read+.el

@@ -57,7 +57,11 @@
   ;; unless that is already set to the ido completer, in which case
   ;; use `completing-read-default'.
   (if (memq completing-read-function
-            '(ido-completing-read+ ido-completing-read))
+            '(ido-completing-read+
+              ido-completing-read
+              ;; Old ido-ubiquitous functions that shouldn't be used
+              completing-read-ido
+              ido-ubiquitous-completing-read))
       'completing-read-default
     completing-read-function)
   "Alternate completing-read function to use when ido is not wanted.