Add some support for setting save panel properties in desktop mode

AppKit/CPSavePanel.j

@@ -5,6 +5,13 @@
 @implementation CPSavePanel : CPPanel
 {
     CPURL   _URL;
+
+    BOOL    _isExtensionHidden @accessors(getter=isExtensionHidden, setter=setExtensionHidden:);
+    BOOL    _canSelectHiddenExtension @accessors(property=canSelectHiddenExtension);
+    BOOL    _allowsOtherFileTypes @accessors(property=allowsOtherFileTypes);
+    BOOL    _canCreateDirectories @accessors(property=canCreateDirectories);
+
+    CPArray _allowedFileTypes @accessors(property=allowedFileTypes);
 }
 
 + (id)savePanel
@@ -12,6 +19,16 @@
     return [[CPSavePanel alloc] init];
 }
 
+- (id)init
+{
+    if (self = [super init])
+    {
+        _canCreateDirectories = YES;
+    }
+
+    return self;
+}
+
 - (CPInteger)runModal
 {
     // FIXME: Is this correct???
@@ -19,7 +36,13 @@
 
     if (typeof window["cpSavePanel"] === "function")
     {
-        var resultObject = window.cpSavePanel(),
+        var resultObject = window.cpSavePanel({
+                isExtensionHidden: _isExtensionHidden,
+                canSelectHiddenExtension: _canSelectHiddenExtension,
+                allowsOtherFileTypes: _allowsOtherFileTypes,
+                canCreateDirectories: _canCreateDirectories,
+                allowedFileTypes: _allowedFileTypes
+            }),
             result = resultObject.button;
 
         _URL = result ? [CPURL URLWithString:resultObject.URL] : nil;