Added externs declarations to header files to handle C++ compilation.

Cleaned up BACnet/IP API a little.

bacnet-stack/tsm.h

@@ -84,6 +84,10 @@ typedef struct BACnet_TSM_Data
   unsigned pdu_len;
 } BACNET_TSM_DATA;
 
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
 bool tsm_transaction_available(void);
 uint8_t tsm_transaction_idle_count(void);
 void tsm_timer_milliseconds(uint16_t milliseconds);
@@ -104,5 +108,9 @@ bool tsm_get_transaction_pdu(
   uint8_t *pdu,
   uint16_t *pdu_len);
 
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
 #endif