Bugfix/confirmed handlers empty service request (#885)

* Added reject in all confirmed service handlers, except GetEventInformation, when confirmed services with zero length occur which rejects with required parameters are missing message.

* Refactored errno use in service using debug_perror. Changed debug_perror usage to debug_fprintf. 

* Updated file and function headers in basic/service modules.

* Changed NDPU priority on confirmed messages to use requested NDPU priority.

* Renamed debug_aprintf to debug_printf_stdout for clarity.

* Convert most debug_fprintf usage to debug_print to reduce text bloat in AVR build

src/bacnet/basic/bbmd/h_bbmd.c

@@ -576,7 +576,7 @@ static void bbmd_read_fdt_ack_handler(
  * @param mtu - the bytes of data to send
  * @param mtu_len - the number of bytes of data to send
  * @return Upon successful completion, returns the number of bytes sent.
- *  Otherwise, -1 shall be returned and errno set to indicate the error.
+ *  Otherwise, -1 shall be returned to indicate the error.
  */
 int bvlc_send_pdu(
     const BACNET_ADDRESS *dest,
@@ -648,7 +648,7 @@ int bvlc_send_pdu(
  * @param result_code - BVLC result code
  *
  * @return Upon successful completion, returns the number of bytes sent.
- *  Otherwise, -1 shall be returned and errno set to indicate the error.
+ *  Otherwise, -1 shall be returned to indicate the error.
  */
 static int
 bvlc_send_result(const BACNET_IP_ADDRESS *dest_addr, uint16_t result_code)