Add some rate limiting to implicit gathers, and always send multicasts to at least one supernode so they can broadcast to old peers (temporary).

node/Multicaster.hpp

@@ -72,9 +72,10 @@ private:
 
 	struct MulticastGroupStatus
 	{
-		MulticastGroupStatus() : lastExplicitGather(0) {}
+		MulticastGroupStatus() : lastExplicitGather(0),lastImplicitGather(0) {}
 
-		uint64_t lastExplicitGather; // time we last gathered members explicitly
+		uint64_t lastExplicitGather;
+		uint64_t lastImplicitGather;
 		std::list<OutboundMulticast> txQueue; // pending outbound multicasts
 		std::vector<MulticastGroupMember> members; // members of this group
 	};