Support IGMPv3 messages with multiple records. Make sure all IGMPv3
messages go through slow path, since they may carry multiple multicast
addresses, unlike IGMPv2.
Tests done:
* multiple addresses in IGMPv3 report are inserted in mdb;
* address is removed from IGMPv3 if record is INCLUDE_MODE;
* reports sent on a burst with same flow all go to userspace;
* IGMPv3 reports go to mrouters, i.e., ports that have issued a query.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com> Acked-by: Flavio Leitner <fbl@sysclose.org> Signed-off-by: Ben Pfaff <blp@nicira.com>