javadoc fixes part 5 (ticket #1894)

core/java/src/net/i2p/crypto/SHA1.java

core/java/src/net/i2p/kademlia/KBucketImpl.java

core/java/src/net/metanotion/io/block/BlockFile.java

core/java/src/net/metanotion/io/block/index/BSkipList.java

router/java/src/net/i2p/data/i2np/I2NPMessage.java

router/java/src/net/i2p/router/TunnelPoolSettings.java

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

...java/src/net/i2p/router/message/GarlicMessageBuilder.java

...et/i2p/router/message/OutboundClientMessageJobHelper.java

.../i2p/router/networkdb/kademlia/FloodfillPeerSelector.java

router/java/src/net/i2p/router/time/NtpMessage.java

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

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

...ava/src/net/i2p/router/transport/ntcp/EstablishState.java

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

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

...r/java/src/net/i2p/router/transport/udp/UDPTransport.java

...r/java/src/net/i2p/router/tunnel/BatchedPreprocessor.java

router/java/src/net/i2p/router/tunnel/TunnelDispatcher.java