Feature/makefile add apps library (#218)

* add BACnet stack library at apps/lib

* convert apps to use apps/lib for smaller binary

* fix -DBACDL_ALL=1 build

* fix piface build

* datalink MAX_MPDU and MAX_HEADER cleanup

* add bip6 to git workflow

* fix system library dependency of BACnet library

Co-authored-by: Steve Karg <skarg@users.sourceforge.net>

src/bacnet/datalink/ethernet.h

@@ -32,8 +32,8 @@
 #include "bacnet/npdu.h"
 
 /* specific defines for Ethernet */
-#define MAX_HEADER (6+6+2+1+1+1)
-#define MAX_MPDU (MAX_HEADER+MAX_PDU)
+#define ETHERNET_HEADER_MAX (6+6+2+1+1+1)
+#define ETHERNET_MPDU_MAX (ETHERNET_HEADER_MAX+MAX_PDU)
 
 #ifdef __cplusplus
 extern "C" {