Add 16 octet constructor

Author: sgryphon

api/IPAddress.h

@@ -63,6 +63,7 @@ class IPAddress : public Printable {
     IPAddress(); // IPv4
     IPAddress(IPType ip_type);
     IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet);
+    IPAddress(uint8_t o1, uint8_t o2, uint8_t o3, uint8_t o4, uint8_t o5, uint8_t o6, uint8_t o7, uint8_t o8, uint8_t o9, uint8_t o10, uint8_t o11, uint8_t o12, uint8_t o13, uint8_t o14, uint8_t o15, uint8_t o16);
     IPAddress(uint32_t address); // IPv4 only; see implementation note
     IPAddress(const uint8_t *address); // IPv4
     IPAddress(IPType ip_type, const uint8_t *address);