Peter M. Groen / libmodbus

- return only useful data client side
- available in TCP when a gateway to RTU is used
- need to add isolated handling of indication/confirmation messages

- more coherent
- namespace
- opaque and smaller context
- usual wording

A new API will be committed to remove the slave in TCP communication.

Original patch by Sisyph (eric-paul).

The ID used at init time will be the device ID of the caller and
the server ID in request functions is the target to reach.

The library is now simpler to include (only one <modbus.h>)
To avoid confusion MB_VERSION defines have been renamed to
LIBMODBUS_VERSION.

This reverts commit df0cf7927249954f15e0aa85b02d21b990fa9af9.
Use <modbus.h> in tests.

- returns -1 on error and set errno
- error recovery system was flawed
- error recovery disabled by default
- remove a malloc

Inspired by the Clutter project and work done by Florian Forster.

This time the change is definitive :)

I don't want to put a burden on build system support anymore

- the return value is used to pass the message length
- remove the hack on exception check in modbus receive
- update tests

- simpler wscript_build files
- reuse VERSION
- add path to config.h

- adjusts various comments on return values
- updated tests
- added entry to MIGRATION

- new function modbus_flush
- new names and values for error defines
- finer recovery on error
- merge TOO_MANY_DATA and INVALID_DATA
- stop unit-test-master at the first error
- FLUSH_OR_RECONNECT_ON_ERROR -> FLUSH_OR_CONNECT_ON_ERROR
- more precise tests in unit-test-master

- MAJOR changes to the API (see MIGRATION)
- New unit tests
- Removed TODO list
- Updated NEWS & MIGRATION files

This change improves the conformance with the PDU and ADU definitions of the
Modbus protocol and reduces the number of additions.

- upgrade to WAF 1.5.3
- smaller WAF scripts
- fix using of modbus.h with WAF
- updated configure.ac and Makefile.am files
- change include paths in test files

- use milliseconds instead of microseconds
- increase the number of loops to 100 000 from 10 000

- new functions modbus_slave_init_listen_tcp, modbus_slave_accept_tcp,
  modbus_slave_slave_receive.
- removed printf in modbus.c: 'Connection closed'
- new slave test, bandwith-slave-many-up
- updated build scripts
- updated MIGRATION document file