Netty 4.1.13.Final发布，Java网络服务框架

Netty 4.1.13.Final 已发布，该版本包括 bug 修复，性能提升和新功能，建议用户升级。详细更新如下：

• Return the correct Future from FixedChannelPool.release() (#6908)

• Close channels that are released to a closed FixedChannelPool (#6907)

• OpenSSL CHACHA20 CipherSuiteConverter updates (#6875)

• Remove synchronized (ReferenceCountedOpenSslContext.class) blocks (#6254)

• AppendableCharSequence not to depend upon IndexOutOfBoundsException for resize (#6845)

• Workaround IBM's J9 JVM getSupportedCipherSuites() returning SSL_ prefix cipher names (#6941)

• DNS Resolver should be more consistent with JDK resolution (#6937)

• KQueue crash due to close/cleanup sequencing (#6922)

• DefaultHttp2ConnectionEncoder#writeHeaders shouldn't send GO_AWAY if stream is closed (#6916)

• transport-native-kqueue libraries should not lazy link (#6915)

• Update Http2SecurityUtil cipher suites (#6914)

• Make Native loading work better with Java 8 (#6884)

• NullPointerException in Lz4FrameEncoder (#6867)

• Use more aggressive expanding strategy in HpackHuffmanDecoder (#6857)

• Do proper bounds-checking in HpackHuffmanDecoder to reduce overhead of IndexOutOfBoundsException creation (#6838)

• Add support for IP_TRANSPARENT socket option (#6835)