Add support for Apple Silicon

-Update classes to read correct Apple Silicon CPU sensor
-Update project to compile a Universal 2 binary. Upgraded Sparkle to 2.1.0 as that was the latest and supports ARM64.
-Add MacBookPro18,1 to Machines.plist

Sparkle.framework/Versions/B/Headers/SPUUpdaterSettings.h

@@ -0,0 +1,61 @@
+//
+//  SPUUpdaterSettings.h
+//  Sparkle
+//
+//  Created by Mayur Pawashe on 3/27/16.
+//  Copyright © 2016 Sparkle Project. All rights reserved.
+//
+
+#if __has_feature(modules)
+#if __has_warning("-Watimport-in-framework-header")
+#pragma clang diagnostic ignored "-Watimport-in-framework-header"
+#endif
+@import Foundation;
+#else
+#import <Foundation/Foundation.h>
+#endif
+#import <Sparkle/SUExport.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ This class can be used for reading certain updater settings.
+ 
+ It retrieves the settings by first looking into the host's user defaults.
+ If the setting is not found in there, then the host's Info.plist file is looked at.
+ */
+SU_EXPORT @interface SPUUpdaterSettings : NSObject
+
+- (instancetype)initWithHostBundle:(NSBundle *)hostBundle;
+
+/**
+ * Indicates whether or not automatic update checks are enabled.
+ */
+@property (readonly, nonatomic) BOOL automaticallyChecksForUpdates;
+
+/**
+ * The regular update check interval.
+ */
+@property (readonly, nonatomic) NSTimeInterval updateCheckInterval;
+
+/**
+ * Indicates whether or not automatically downloading updates is allowed to be turned on by the user.
+ */
+@property (readonly, nonatomic) BOOL allowsAutomaticUpdates;
+
+/**
+ * Indicates whether or not automatically downloading updates is enabled by the user or developer.
+ *
+ * Note this does not indicate whether or not automatic downloading of updates is allowable.
+ * See `-allowsAutomaticUpdates` property for that.
+ */
+@property (readonly, nonatomic) BOOL automaticallyDownloadsUpdates;
+
+/**
+ * Indicates whether or not anonymous system profile information is sent when checking for updates.
+ */
+@property (readonly, nonatomic) BOOL sendsSystemProfile;
+
+@end
+
+NS_ASSUME_NONNULL_END