Rename methods of EmbeddedChannel and mark old ones as @deprecated
Multiple optimizations in the HttpObjectDecoder

* Minimize allocation of StringBuilder and also minimize char array copy
* Try to detect HttpVersion without calling toUpperCase() for performance reasons
Simplify handler invocations in DefaultChannelHandlerContext

- Sometimes we delegated executor.inEventLoop() to the next context and sometimes we did not.  Now we always check inEventLoop() before delegating.
[#1683] Mark unused ChannelOption @deprecated, to prepare for removal in 4.1.0.Final
Fix a bug in NioSocketChannel.doWrite() where flush() triggered from a ChannelFutureListener is ignored

- Fixes #1679
Fix checkstyle
Make sure ChannelHandler.handlerRemoved() is invoked while handler methods are not running

- Fixes #1664
Merge remote-tracking branch upstream/$:{upbranch}