Bump netty version to 4.0.17.Final | Allow Linux to take advatange of th...

...e superior Epoll class sockets while still leaving NIO sockets implemented for Non-Linux operating systems.

Been working with Epoll a lot recently, seems to reduce latency, CPU usage, lost packets, dropped connections, as well as increase overall capacity. Though I would take a swing at pushing it to BungeeCord but still leaving NioSocket implementation for Non-Linux users.