Upgrade to netty 4.0.18.Final
Merge pull request #1602 from normanmaurer/netty_upgrade_4_0_18

Upgrade to netty 4.0.18.Final
Optimize BindingsImpl#route() by removing 2nd checks to HDR_ROUTE_TO_IDS and HDR_GROUP_ID properties.
Optimization in accordance to the following code comment:
"// TODO this is a little inefficient since we do the lookup once to see if the property is there, then do it again to remove the actual property"
Only copy the originnal message in the DivertImpl, if it is forwarded to somewhere else.
Optimization in accordance to the following code comment:
"TODO we can optimise this so it doesn't copy if it's not routed anywhere else"
[HORNETQ-1302] Embedded server without persistence creates a server.lock file
Brought InVMNodeManager from test scope to distribution and instantiate it, in case the configuration is set with no persistence.