Create mechanism to inject additional_data into multiplexed JChannel

ClusterPartition requires the Channel it uses to be configured with additional_data, which it uses to ensure a unique node id. Need to ensure this data is present if the channel was already created/connected via the multiplexer/JChannelFactory.

This is a temporary requirement until JBAS-3425 is completed.

I'll implement this by subclassing JChannelFactory with an AS-specific version that creates and injects the additional_data before returning a channel.