Unify major syncing detection (#2699)

* simplify major sync detection

* fix typos

* fix merge

* more realistic EthTester

* add new synced state

ethcore/src/snapshot/watcher.rs

@@ -46,9 +46,7 @@ impl<F> Oracle for StandardOracle<F>
 	}
 
 	fn is_major_syncing(&self) -> bool {
-		let queue_info = self.client.queue_info();
-
-		(self.sync_status)() || queue_info.unverified_queue_size + queue_info.verified_queue_size > 3
+		(self.sync_status)()
 	}
 }
 
@@ -200,4 +198,4 @@ mod tests {
 	fn doesnt_fire_before_history() {
 		harness(vec![10, 11], 10, 5, None);
 	}
-}
+}