[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.
The first check verifies that in contains all data.  If it doesn't we return and wait for more data to trigger again.  We will need to frame the decoding when the messages are variable length (write path, thrift).  Will leave that until its needed.