Implement DotNetty Transport

[rogeralsing]

Netty has been ported to .NET by MS and we are aiming to replace the current transport with a new transport built ontop of DotNetty.
https://github.com/Azure/DotNetty

Given the problems shown in #1355 and issues relating to message order I think we should step up our efforts on this one.

[edit] marking this critical as 300 msg/sec is simply not acceptable

[rogeralsing]

We could build this as a stand alone PoC under up for grabs, just to get some effort going here.

[rogeralsing]

Added a fork of DotNetty here https://github.com/akkadotnet/DotNetty, incase MS drops the effort, we can continue it here.

[Aaronontheweb]

I'm working on implementing the missing pieces in DotNetty to make it wire-compatible with Helios - mostly a bunch of decoding stuff. Should take me another 12-16 hours worth of work (depending on how quickly I can get the testing infrastructure ported correctly)

[Aaronontheweb]

Took a while, but DotNetty should be wire-compatible with Helios now: Azure/DotNetty#40

Keep an eye on that PR.

[Aaronontheweb]

cc @SeanFarrow is going to take a stab at this

[Aaronontheweb]

Closed by #2444