Add uc_log_delete_destination.

Make a copy of ident for syslog destination

src/ucore_logging.h

@@ -111,11 +111,25 @@ struct uc_log_destination *uc_log_new_file(const char *filename, int log_level,
 void uc_log_add_destination(struct uc_log_destination *dest);
 
 /** Remove a log destination.
+ *  Note that this does not free the destination, it can be readded later.
+ *  For file destination, the log file is NOT closed.
  *
  * @param dest The uc_log_destination to remove.
  */
 void uc_log_remove_destination(struct uc_log_destination *dest);
 
+/** Remove and free a destination.
+ * This frees the memory allocated to the destination. For
+ * UC_LDEST_FILE the log file is closed.
+ *
+ * If the destination is not already removed, it will be removed first,
+ * there's no need to call uc_log_remove_destination first.
+ * The destination cannot be used again after this function has been called.
+ *
+ * @param dest The destination to delete.
+ */
+void uc_log_delete_destination(struct uc_log_destination *dest);
+
 /** Change the log level of a module.
  *
  * @param module The module to change, matched against the id member of a struct uc_log_module