classForKeyedArchiver for remaining NSCFS types

Author: lhoward

Foundation/NSCFArray.swift

@@ -42,6 +42,10 @@ internal final class _NSCFArray : NSMutableArray {
     override func removeObjectAtIndex(index: Int) {
         CFArrayRemoveValueAtIndex(_cfMutableObject, index)
     }
+    
+    override var classForKeyedArchiver: AnyClass? {
+        return NSMutableArray.self
+    }
 }
 
 internal func _CFSwiftArrayGetCount(array: AnyObject) -> CFIndex {

Foundation/NSCFDictionary.swift

@@ -87,6 +87,10 @@ internal final class _NSCFDictionary : NSMutableDictionary {
     override func setObject(anObject: AnyObject, forKey aKey: NSObject) {
         CFDictionarySetValue(_cfMutableObject, unsafeBitCast(aKey, UnsafePointer<Void>.self), unsafeBitCast(anObject, UnsafePointer<Void>.self))
     }
+    
+    override var classForKeyedArchiver: AnyClass? {
+        return NSMutableDictionary.self
+    }
 }
 
 internal func _CFSwiftDictionaryGetCount(dictionary: AnyObject) -> CFIndex {

Foundation/NSCFSet.swift

@@ -27,4 +27,8 @@ internal final class _NSCFSet : NSMutableSet {
     required init(capacity numItems: Int) {
         fatalError()
     }
+    
+    override var classForKeyedArchiver: AnyClass? {
+        return NSMutableSet.self
+    }
 }