Avoid usage of [event keyCode].

Key codes have platform and browser specific behaviours.

AppKit/CPDragServer.j

@@ -456,8 +456,8 @@ var CPDraggingSource_draggedImage_movedTo_          = 1 << 0,
     }
     else if (type === CPKeyDown)
     {
-        var keyCode = [anEvent keyCode];
-        if (keyCode === CPEscapeKeyCode)
+        var characters = [anEvent characters];
+        if (characters === CPEscapeFunctionKey)
         {
             _dragOperation = CPDragOperationNone;
             [self draggingEndedInPlatformWindow:platformWindow globalLocation:CGPointMakeZero() operation:_dragOperation];

AppKit/CPTextField.j

@@ -672,7 +672,9 @@ CPTextFieldStatePlaceholder = CPThemeState("placeholder");
 
 - (void)keyDown:(CPEvent)anEvent
 {
-    if ([anEvent keyCode] === CPReturnKeyCode)
+    var characters = [anEvent characters];
+    // Treat \r and \n the same. See issue #710.
+    if (characters === CPNewlineCharacter || characters === CPCarriageReturnCharacter)
     {
         // selectText: has a side effect - it can change first responder of the window
         // we have to prevent such behaviour inside this method because target should be able to change first responder after receiving action.