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/bacreal.h

@@ -27,39 +27,48 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <stddef.h>
+#include "bacnet/bacnet_stack_exports.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
 
+    BACNET_STACK_EXPORT
     int decode_real_safe(
         uint8_t * apdu,
         uint32_t len_value,
         float *real_value);
 
+    BACNET_STACK_EXPORT
     int decode_real(
         uint8_t * apdu,
         float *real_value);
 
+    BACNET_STACK_EXPORT
     int decode_context_real(
         uint8_t * apdu,
         uint8_t tag_number,
         float *real_value);
+    BACNET_STACK_EXPORT
     int encode_bacnet_real(
         float value,
         uint8_t * apdu);
+    BACNET_STACK_EXPORT
     int decode_double(
         uint8_t * apdu,
         double *real_value);
+    BACNET_STACK_EXPORT
     int decode_context_double(
         uint8_t * apdu,
         uint8_t tag_number,
         double *double_value);
+    BACNET_STACK_EXPORT
     int decode_double_safe(
         uint8_t * apdu,
         uint32_t len_value,
         double *double_value);
 
+    BACNET_STACK_EXPORT
     int encode_bacnet_double(
         double value,
         uint8_t * apdu);
@@ -67,8 +76,10 @@ extern "C" {
 #ifdef TEST
 #include "ctest.h"
 
+    BACNET_STACK_EXPORT
     void testBACreal(
         Test * pTest);
+    BACNET_STACK_EXPORT
     void testBACdouble(
         Test * pTest);
 #endif