Quick fix for initWithCapacity: not working on CPMutableArray.

Reviewed by me.

Foundation/CPArray/CPArray.j

@@ -175,6 +175,12 @@ var concat = Array.prototype.concat,
     FORWARD_TO_CONCRETE_CLASS();
 }
 
+// FIXME: This should be defined in CPMutableArray, not here.
+- (id)initWithCapacity:(unsigned)aCapacity
+{
+    FORWARD_TO_CONCRETE_CLASS();
+}
+
 // Querying an array
 /*!
     Returns \c YES if the array contains \c anObject. Otherwise, it returns \c NO.

Foundation/CPArray/CPMutableArray.j

@@ -29,10 +29,10 @@
     Initializes an array able to store at least \c aCapacity items. Because CPArray
     is backed by JavaScript arrays, this method ends up simply returning a regular array.
 */
-- (id)initWithCapacity:(unsigned)aCapacity
+/*- (id)initWithCapacity:(unsigned)aCapacity
 {
     return self;
-}
+}*/
 
 // Adding and replacing objects
 /*!

Foundation/CPArray/_CPJavaScriptArray.j

@@ -102,6 +102,11 @@ var concat = Array.prototype.concat,
     return array;
 }
 
+- (id)initWithCapacity:(CPUInteger)aCapacity
+{
+    return self;
+}
+
 - (BOOL)count
 {
     return self.length;