Started on refactoring of address caching.

1. Added support for building address binding list for device object
2. Changed table traversal code to use pointers instead of array indexes as this produces much more efficient code on many smaller processors where multiplication is expensive
3. fixed issue where binding requests can be overwritten by first I AM that comes along.
4. Converted multiple state variables in cache entries to single flag bitmap.

bacnet-stack/include/address.h

@@ -86,6 +86,10 @@ extern "C" {
         unsigned max_apdu,
         BACNET_ADDRESS * src);
 
+    int address_list_encode(
+        uint8_t * apdu,
+        unsigned apdu_len);
+        
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */