[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 is how errors are defined from nio.

Header will be as follows:
-blockid
0
0

This is not the cleanest way to return errors, but didn't want to change the logic in this patch.