Merge pull request #2824 from daboe01/cpdocumentcontroller-return-type-fix

fixed: return type of openUntitledDocumentOfType:display:

AppKit/CPDocumentController.j

@@ -106,7 +106,7 @@ var CPSharedDocumentController = nil;
     @param aType the type of the new document
     @param shouldDisplay whether to display the document on screen
 */
-- (void)openUntitledDocumentOfType:(CPString)aType display:(BOOL)shouldDisplay
+- (CPDocument)openUntitledDocumentOfType:(CPString)aType display:(BOOL)shouldDisplay
 {
     var theDocument = [self makeUntitledDocumentOfType:aType error:nil];