- Arduino example added.
  Tested with Arduino Mega 2560 R3 using Modbusino over USB at 115200 bps.
- New parameters in config file.
  HAL_MODULE_NAME, MB_RESPONSE_TIMEOUT_MS and MB_BYTE_TIMEOUT_MS.
- New HAL pin "num_errors" for each transaction. num_errors = 0 if last
  transaction OK, else the count of failed transactions.
- Fix a bug, OPTIONAL's parameters may be 0 instead of default value if
  not specified in 1st transaction.

Signed-off-by: Michael Haberler <git@mah.priv.at>

- Mb2hal now uses libmodbus3 instead of the old libmodbus file
  located in src/hal/user_comps/modbus.c used by gs2_vfd.c
  # Also fix a TIMEOUT bug (due to this unpatched old libmodbus file).
- Better INI file documentation (HOW-TO).
- Better Submakefile.
- Source code cleaned and reordered.
  # Now is posible to add new functionallity.

See LogBook.txt for more information.

Signed-off-by: Michael Haberler <git@mah.priv.at>

Nothing big, two instances of dead initialization (so, a variable is
explicitly set at define-time, but then written to again before being read).

Signed-off-by: Sebastian Kuzminsky <seb@highlab.com>

This reverts commit ca835b429478324639df779e26005ca43b8917d1.

Victor says it is needed.

Userspace HAL component to communicate with one or
more Modbus devices.

Tests:
- TCP some functions = Remote IO Delta RTU-EN01,
  24 inputs, 8 outputs.
- RS232 some functions = Servo Drive Delta ASDA-B (1021-A 1Kw).
- TCP all functions = MoD_RsSim V8.20 (www.plcsimulator.org)
  on Windows XP SP3.

Signed-off-by: Michael Haberler <git@mah.priv.at>