Export symbols in order to support shared libraries (#54)

* Add BAC_ROUTING compile definition

* Reorder cmake

* Fix OpenSSL support: support both 1.0 and 1.1t pus

* Explicitly export symbols, hidden by default

* Build shared libraries on travis using cmake

* Learn Makefile about static library

* Fix build using mingw with cmake

* Do not cleanup twice or after potential free

src/bacnet/basic/service/h_upt.h

@@ -32,6 +32,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <stdint.h>
+#include "bacnet/bacnet_stack_exports.h"
 #include "bacnet/bacdef.h"
 #include "bacnet/bacenum.h"
 #include "bacnet/apdu.h"
@@ -41,10 +42,12 @@
 extern "C" {
 #endif /* __cplusplus */
 
+    BACNET_STACK_EXPORT
     void handler_unconfirmed_private_transfer(
         uint8_t * service_request,
         uint16_t service_len,
         BACNET_ADDRESS * src);
+    BACNET_STACK_EXPORT
     void private_transfer_print_data(
         BACNET_PRIVATE_TRANSFER_DATA *private_data);