HEADS UP: MLDv2 merge commencing

Hi all,

I have begun merging pieces of MLDv2 (Source-specific multicast for 
IPv6) to the HEAD tree.
To begin with I've pushed some bug fixes from this spin in, as well as 
the parts which won't depend on the kernel support having to be present.

A full UPDATING entry will be made once the remaining kernel pieces have 
been pushed in. I'm currently trying to get a 'make universe' pass so I 
can recompute the VIMAGE structure sizes.
[An additional side-effect of the MLDv2 spin is that the ip6_mrouter 
socket gets virtualized, that's a sticking point just now.]

If there are any build issues, please let me know ASAP.

thanks,
BMS