Add setmtu command, fix bond lifetime issue

include/ZeroTierOne.h

@@ -1194,7 +1194,7 @@ typedef struct
 		uint64_t mac; /* MAC in lower 48 bits */
 		uint32_t adi; /* Additional distinguishing information, usually zero except for IPv4 ARP groups */
 	} multicastSubscriptions[ZT_MAX_MULTICAST_SUBSCRIPTIONS];
-	
+
 	/**
 	 * Network specific DNS configuration
 	 */
@@ -1327,6 +1327,11 @@ typedef struct
 	 */
 	float packetErrorRatio;
 
+	/**
+	 * Number of flows assigned to this path
+	 */
+	uint16_t assignedFlowCount;
+
 	/**
 	 * Address scope
 	 */