run santactl as a sync daemon (#129)

* run santactl as a sync daemon

Source/santad/SNTSyncdQueue.h

@@ -0,0 +1,28 @@
+/// Copyright 2016 Google Inc. All rights reserved.
+///
+/// Licensed under the Apache License, Version 2.0 (the "License");
+/// you may not use this file except in compliance with the License.
+/// You may obtain a copy of the License at
+///
+///    http://www.apache.org/licenses/LICENSE-2.0
+///
+///    Unless required by applicable law or agreed to in writing, software
+///    distributed under the License is distributed on an "AS IS" BASIS,
+///    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+///    See the License for the specific language governing permissions and
+///    limitations under the License.
+
+@class SNTStoredEvent;
+@class SNTXPCConnection;
+
+@interface SNTSyncdQueue : NSObject
+
+@property(nonatomic) SNTXPCConnection *syncdConnection;
+@property(copy) void (^invalidationHandler)();
+@property(copy) void (^acceptedHandler)();
+
+- (void)addEvent:(SNTStoredEvent *)event;
+- (void)startSyncingEvents;
+- (void)stopSyncingEvents;
+
+@end