Netty updates


* Bumped Netty version
* Applied socket settings to Netty
* Made initial connection async but will block on first read / write
* Made AsynchronousSocketChannelStream inline with other streams 
  it now throws a MongoSocketOpenException if connection fails

Refs JAVA-1155
I don't think we should throw a Netty-specific exception.  It will create un-portable code for people that switch between async implementations.