Feature/refactor bacnet ipv4 add unit tests (#64)

* refactor BACnet/IPv4 BVLC into encode-decode library with unit tests
Added Read-Broadcast-Distribution-Table encoding and unit test.
Added Read-Broadcast-Distribution-Table-Ack encoding and unit test.
Added Read-Foreign-Device-Table-Ack encoding and unit test.
Added some BDT/FDT diff copy functions with unit tests
Added some FDT add and delete entry functions with unit tests
Added some BDT set append and clear entry functions with unit tests
Added some BIPv4 address conversion functions with unit tests
Added non-BBMD handling unit test
Added basic unit test for BBMD handler
Added BBMD broadcast mask get set and unit tests
Added IPv6 maintenance timer.
Added ReadFDT app
Fixed ReadBDT app
Added Who-Is to Makefile for individual app build
Fixed debugging code blocks projects by swapping bip.c for h_bbmd.c module.
Ported BACnet/IPv4 to refactored BVLC for Linux, BSD, Windows
Fix datalink debug for DLENV module
Improve BIPv4 linux driver debug info
Added BDT mask functions
Reduce debug info clutter in Who-Is app by using environment option
Fix TTL seconds upper bounds addition
Fix CIDR prefix calculation on Linux BIPv4.
Convert BSD BIPv4 to BVLCv4
Fix CMake build for BIPv4 (Linux, BSD, Windows)
Added [U]nsigned to 0xBAC0 constants
Cleanup POSIX and Win32 API sockets
Remove unnecessary file scope variable initialization
Fix routed NPDU to depend on datalink; fix warning
Remove OS dependent network code from gateway
Enable BBMD client in library by default
Co-authored-by: Steve Karg <skarg@users.sourceforge.net>
Co-authored-by: Steve Karg <steve.karg@legrand.us>

ports/arduino_uno/bip.h

@@ -36,8 +36,6 @@
 
 #define BVLL_TYPE_BACNET_IP (0x81)
 
-extern bool BIP_Debug;
-
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
@@ -80,9 +78,9 @@ extern "C" {
 
         unsigned timeout);      /* milliseconds to wait for a packet */
 
-    /* use network byte order for setting */
+    /* use host byte order for setting */
     void bip_set_port(uint16_t port);
-    /* returns network byte order */
+    /* returns host byte order */
     uint16_t bip_get_port(void);
 
     /* use network byte order for setting */
@@ -102,6 +100,7 @@ extern "C" {
        an IP address in network byte order */
     long bip_getaddrbyname(const char *host_name);
 
+    void bip_debug_enable(void);
 
 #ifdef __cplusplus
 }