Add functions to enable/disable debug logging (#280)

* Add "bip_debug_disable()"

* Add "bvlc_debug_disable()"

* Add setters for BIP_DL_Debug (BBMD registration debug logging)

src/bacnet/datalink/bip.h

@@ -113,6 +113,9 @@ extern "C" {
     BACNET_STACK_EXPORT
     void bip_debug_enable(void);
 
+    BACNET_STACK_EXPORT
+    void bip_debug_disable(void);
+
     BACNET_STACK_EXPORT
     int bip_get_socket(void);