[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.
Ok, so the message can be -1 in the error case, hence the abs.  In the netty case, this is always positive, so the abs is not needed.  Will remove.