add initialization and deinitialization.

include/nfc/nfc.h

@@ -62,6 +62,10 @@
 extern  "C" {
 #  endif                        // __cplusplus
 
+/* Library initialization/deinitialization */
+  NFC_EXPORT void nfc_init();
+  NFC_EXPORT void nfc_exit();
+
 /* NFC Device/Hardware manipulation */
   NFC_EXPORT bool nfc_get_default_device (nfc_connstring *connstring);
   NFC_EXPORT nfc_device *nfc_open (const nfc_connstring connstring);

libnfc/nfc.c

@@ -61,6 +61,26 @@ const struct nfc_driver *nfc_drivers[] = {
   NULL
 };
 
+/**
+ * @brief Initialize libnfc.
+ *
+ */
+void 
+nfc_init()
+{
+  log_init ();
+}
+
+/**
+ * @brief Deinitialize libnfc.
+ *
+ */
+void 
+nfc_exit()
+{
+  log_fini ();
+}
+
 /**
  * @brief Get the defaut NFC device
  * @param connstring \a nfc_connstring pointer where the default connection string will be stored