Convert Xcode code landmarks from Objective-C to native Javascript

While objc `#pragma mark` works in objj files, it requires a preprocessor to handle the directive.

// MARK: is the fully functional and correct Objective-J variant.

Foundation/CPSet/CPMutableSet.j

@@ -173,8 +173,8 @@
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Category: CPKeyValueCoding
+// MARK: Category: CPKeyValueCoding
 
 @implementation CPSet (CPKeyValueCoding)
 
@@ -247,8 +247,8 @@
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Key-Value Observing Extensions
+// MARK: Key-Value Observing Extensions
 
 @implementation CPObject (CPSetKVO)
 
@@ -274,8 +274,8 @@
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Key-Value Observing Proxy Implementation
+// MARK: Key-Value Observing Proxy Implementation
 
 @implementation _CPKVCSet : CPMutableSet
 {

Foundation/CPSet/_CPSet.j

@@ -295,8 +295,8 @@
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Category: CPCopying
+// MARK: Category: CPCopying
 
 @implementation CPSet (CPCopying)
 
@@ -312,8 +312,8 @@
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Category: CPCoding
+// MARK: Category: CPCoding
 
 var CPSetObjectsKey = @"CPSetObjectsKey";
 
@@ -331,8 +331,8 @@ var CPSetObjectsKey = @"CPSetObjectsKey";
 
 @end
 
-#pragma mark -
+// MARK: -
-#pragma mark Private Allocation Placeholder
+// MARK: Private Allocation Placeholder
 
 var _CPSharedPlaceholderSet = nil;