[TACHYON-62] Netty

Netty implementation of the data server.

This patch is not done yet.  Its intent is to show the work I have right now for commenting.

This PR should not be merged until performance results come in.
That's fine, the intent is to kill the process since we can't start up the server.

Propagate will throw a runtime exception, so same intent.

To make this more generic, I'll move this check inside Netty so it matches nio