add netty http plugin

[yinshujin]

Hello, we now have to do netty use the http server, there are plans to add a plugin for netty httpServer do?

[iwin4aids]

Netty is always an underlying communication framework of remote calling usage, im looking forward to a netty support plugin.

[linking12]

It is more useful for gateway, because high performance gateway is a netty server,also it is a netty client;