[CoreFoundation] Hopefully fix a Ruby constant lookup issue.

A few people have reported an issue where the CFAutoRelease constant
could not be found from the singleton method.

* CocoaPods/CocoaPods#2632
* CocoaPods/CocoaPods#2739

I have been unable to reproduce this, but because the issue has been
reported by more than one person, I'm adding this just to be sure.

CHANGELOG.md

@@ -6,7 +6,7 @@
 
 * `Project` Make `#==` a fast shallow comparison method, which operates only on
   its root object UUID and its path on disk. For full data comparisons, use the
-  `#eql?` method instead.
+  `#eql?` method instead.  
   [Eloy Durán](https://github.com/alloy)
   [Xcodeproj#216](https://github.com/CocoaPods/Xcodeproj/pull/216)
 
@@ -19,6 +19,15 @@
   [Eloy Durán](https://github.com/alloy)
   [Xcodeproj#216](https://github.com/CocoaPods/Xcodeproj/pull/216)
 
+###### Bug Fixes
+
+* `CoreFoundation` Hopefully fix a Ruby constant lookup issue. We have been
+  unable to reproduce this, but since more than one person has reported it,
+  we're including this fix in the hope it fixes this esoteric issue.  
+  [Eloy Durán](https://github.com/alloy)
+  [CocoaPods#2632](https://github.com/CocoaPods/CocoaPods/issues/2632)
+  [CocoaPods#2739](https://github.com/CocoaPods/CocoaPods/issues/2739)
+
 
 ## 0.20.0
 

lib/xcodeproj/plist_helper.rb

@@ -310,10 +310,13 @@ def self.CFTypeDictionaryValueCallBacks
   # This pointer will assign `CFRelease` as the free function when
   # dereferencing the pointer.
   #
+  # @note This means that the object will *not* be released if it's not
+  #       dereferenced, but that would be a leak anyways, so be sure to do so.
+  #
   def self.CFTypeRefPointer
     pointer = Fiddle::Pointer.malloc(Fiddle::SIZEOF_INTPTR_T, free_function)
     def pointer.ptr
-      CFAutoRelease(super)
+      ::CoreFoundation.CFAutoRelease(super)
     end
     pointer
   end