upgrade netty to 3.4.5.Final

When I upgraded HornetQ to 2.2.19.Final, I did not update Netty to the same version that HornetQ requires (from 3.2.6.Final to 3.4.5.Final).

What's more, with this version, Netty changeed its groupId in Maven from org.jboss.netty to io.netty.

HornetQ is not the only component that depends on Netty (jbossws uses it too) and I am not sure jbossws is ready to update its version of Netty.

Since the groupId of Netty changed, I propose to add a new module io.netty and upgrade its Netty versiontto 3.4.5.Final. HornetQ modules will then depend on that module.

I will not change the current org.jboss.netty module (that is used by jbossws)