Upgrade Wake to depend on Netty 4.0.x 

This pull request upgrades Wake's Netty dependency from 3.x to 4.0.x. 
Netty 4.0.x introduced quite big API changes and optimized implementations. 
To get the benefits of the new implementation, we ported Wake on Netty 4.0.x.
The main changes are made in the `com.microsoft.wake.remote.transport.netty` package.
- Use of ChannelInitializer and ChannelInboundHandlerAdapter
- Use of new bootstrapping APIs with NioEventLoopGroup
- Use of new channel state transitions
- Use of new Netty buffer APIs
- Rewritten ChunkReadWriteHandler