startup/shutdown synchronization in several places

router/java/src/net/i2p/router/InNetMessagePool.java

router/java/src/net/i2p/router/MessageHistory.java

router/java/src/net/i2p/router/MessageValidator.java

router/java/src/net/i2p/router/Router.java

router/java/src/net/i2p/router/client/ClientManager.java

...va/src/net/i2p/router/client/ClientManagerFacadeImpl.java

...er/networkdb/kademlia/FloodfillNetworkDatabaseFacade.java

...ter/networkdb/kademlia/KademliaNetworkDatabaseFacade.java

...src/net/i2p/router/peermanager/PeerManagerFacadeImpl.java

router/java/src/net/i2p/router/peermanager/PeerTestJob.java

...va/src/net/i2p/router/transport/CommSystemFacadeImpl.java

...va/src/net/i2p/router/transport/FIFOBandwidthLimiter.java

...a/src/net/i2p/router/transport/FIFOBandwidthRefiller.java

...r/java/src/net/i2p/router/transport/TransportManager.java

...a/src/net/i2p/router/transport/ntcp/NTCPSendFinisher.java

router/java/src/net/i2p/router/transport/ntcp/Reader.java

router/java/src/net/i2p/router/transport/ntcp/Writer.java

router/java/src/net/i2p/router/transport/udp/ACKSender.java

...rc/net/i2p/router/transport/udp/EstablishmentManager.java

...net/i2p/router/transport/udp/InboundMessageFragments.java