Multicast support

[James Chamberlain]

Is the multicast functionality complete for both input and output? I  
see that camel uses MINA, but the documentation for MINA says that it  
does not currently support multicast because it's not in the JVM. They  
have an open jira issue https://issues.apache.org/jira/browse/DIRMINA-438 
, but it does not look completed? I could see how it could support  
outbound because it's not that different, but inbound is different and  
I would not think that it would work without specific support added  
for it.

- James