[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.
Netty docs redirect to http://docs.oracle.com/javase/7/docs/api/java/net/StandardSocketOptions.html?is-external=true#SO_SNDBUF, which says system dependent.