implement save request on OSX, add Quick Look extentions

PanoQL/PreviewViewController.m

@@ -0,0 +1,45 @@
+//
+//  PreviewViewController.m
+//  PanoQL
+//
+//  Created by Omar Mohamed Ali Mudhir on 15/06/18.
+//  Copyright © 2018 OmixLab ltd. All rights reserved.
+//
+
+#import "PreviewViewController.h"
+#import <QuickLook/QuickLook.h>
+
+@interface PreviewViewController () <QLPreviewingController>
+
+@end
+
+@implementation PreviewViewController
+
+- (void)viewDidLoad {
+    [super viewDidLoad];
+    // Do any additional setup after loading the view from its nib.
+}
+
+- (void)didReceiveMemoryWarning {
+    [super didReceiveMemoryWarning];
+    // Dispose of any resources that can be recreated.
+}
+
+- (void)preparePreviewOfSearchableItemWithIdentifier:(NSString *)identifier queryString:(NSString * _Nullable)queryString completionHandler:(void (^)(NSError * _Nullable))handler {
+    // Perform any setup necessary in order to prepare the view.
+    
+    // Call the completion handler so Quick Look knows that the preview is fully loaded.
+    // Quick Look will display a loading spinner while the completion handler is not called.
+    handler (nil);
+}
+
+/*
+ * Implement this method if you support previewing files.
+ * Add the supported content types to the QLSupportedContentTypes array in the Info.plist of the extension.
+ *
+- (void)preparePreviewOfFileAtURL:(NSURL *)url completionHandler:(void (^)(NSError * _Nullable))handler {
+    handler(nil);
+}
+ */
+
+@end