Misc. Javadoc fixes

...eaming/java/src/net/i2p/client/streaming/impl/Packet.java

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

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

core/java/src/net/i2p/data/LeaseSet2.java

core/java/src/net/i2p/util/FileUtil.java

...er/java/src/net/i2p/router/crypto/ratchet/RatchetSKM.java