blockpool stability fixes:

- follow up locks and fix them
- chainManager: call SetQueued for parentErr future blocks, uncomment TD checks, unskip test
- make ErrIncorrectTD non-fatal to be forgiving to genuine mistaken nodes (temp) but demote them to guard against stuck best peers.
- add purging to bounded nodeCache (config nodeCacheSize)
- use nodeCache when creating blockpool entries and let non-best peers add blocks (performance boost)
- minor error in addError
- reduce idleBestPeerTimeout to 1 minute
- correct status counts and unskip status passing status test
- glogified logging

eth/protocol.go

@@ -299,7 +299,7 @@ func (self *ethProtocol) handle() error {
 		// to simplify backend interface adding a new block
 		// uses AddPeer followed by AddBlock only if peer is the best peer
 		// (or selected as new best peer)
-		if best, _ := self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect); best {
+		if _, suspended := self.blockPool.AddPeer(request.TD, hash, self.id, self.requestBlockHashes, self.requestBlocks, self.protoErrorDisconnect); !suspended {
 			self.blockPool.AddBlock(request.Block, self.id)
 		}
 
@@ -384,11 +384,9 @@ func (self *ethProtocol) sendStatus() error {
 }
 
 func (self *ethProtocol) protoErrorDisconnect(err *errs.Error) {
-	//err.Log(self.peer.Logger)
 	err.Log(glog.V(logger.Info))
-	/*
-		if err.Fatal() {
-			self.peer.Disconnect(p2p.DiscSubprotocolError)
-		}
-	*/
+	if err.Fatal() {
+		self.peer.Disconnect(p2p.DiscSubprotocolError)
+	}
+
 }