More performance optimizations (#1649)

* Use tree index for DB

* Set uncles_hash, tx_root, receipts_root from verified block

* Use Filth instead of a bool

* Fix empty root check

* Flush block queue properly

* Expunge deref

parity/main.rs

@@ -447,7 +447,7 @@ fn execute_import(conf: Configuration, panic_handler: Arc<PanicHandler>) {
 			Err(BlockImportError::Import(ImportError::AlreadyInChain)) => { trace!("Skipping block already in chain."); }
 			Err(e) => die!("Cannot import block: {:?}", e)
 		}
-		informant.tick(client.deref(), None);
+		informant.tick(&*client, None);
 	};
 
 	match format {
@@ -473,6 +473,10 @@ fn execute_import(conf: Configuration, panic_handler: Arc<PanicHandler>) {
 			}
 		}
 	}
+	while !client.queue_info().is_empty() {
+		sleep(Duration::from_secs(1));
+		informant.tick(&*client, None);
+	}
 	client.flush_queue();
 }