Peter M. Groen / libmodbus

The previous implementation dereferenced a type-puned pointer, which is
illegal according to ANSI C. Some newer versions of GCC will complain
about this. This implementation uses "memcpy" to avoid this problem.

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

It occurs on first occurence of slave timeout (found with Valgrind 3.3.0).
Reported by Henrik Munktell.

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

Reported by Henrik Munktell.

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

Reported and tested by Yishin Li.

Real fix #333455 - IPTOS_LOWDELAY not supported on cygwin
Thank to Yishin Li for the better problem description.

- check IPTOS_LOWDELAY define in configure
- generate a config.h
- include the generated config.h in modbus.c

- 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

- same values (2)
- man of socket() says PF_INET (packet family)
- AF_INET (address family) for addresses

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

The maximum length of the ADU is 260 in TCP not 256.

Improve the conformance to the Modbus protocol.
MAX_STATUS: 800 -> 2000
MAX_REGISTERS: 100 -> 125

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

- separate tests directory
- regroup modbus.h and modbus.c in the same dir
- updated waf scripts
- updated autotools files
- bump application version to 1.9.0
- bump library number to 2.0.0

- modbus.[ch] are LGPL
- test-modbus-master.c and test-modbus-slave.c are GPL

- move modbus.h => include/modbus/
- create a pkgconfig file (module.pc)
- install modbus.h in $(includedir)
- new path to reach modbus.h

- Fix #191039 reported by Todd Denniston
    modbus.h is not installed at prefix

- (error_treat): used string instead of message
- added a define for each function code supported
- added compute_query_size_header/data functions to read messages
- added new function manage_query to manage queries and send the right
  response
- s/receive_response/receive_msg/
- major changes to receive_msg to handle query
- changed return value of check_crc16
- added response_io_status
- comments
- added functions to allocate/free a modbus mapping