Add C++ compatibility, this fix Issue 16.

src/libnfc.h

@@ -32,6 +32,10 @@
 #include "defines.h"
 #include "types.h"
 
+#ifdef __cplusplus 
+    #define NFCAPI extern "C" {
+#endif // __cplusplus
+
 /**
  * @fn dev_info* nfc_connect(nfc_device_desc_t* pndd)
  * @brief Connect to a NFC device
@@ -231,5 +235,10 @@ bool nfc_target_send_bytes(const dev_info* pdi, const byte_t* pbtTx, const size_
  */
 bool nfc_target_send_dep_bytes(const dev_info* pdi, const byte_t* pbtTx, const size_t szTxLen);
 
+#ifdef __cplusplus 
+}
+#endif // __cplusplus
+
+
 #endif // _LIBNFC_H_