Peter M. Groen / libmodbus

Thanks to oldfaber and endrelovas.

Simply run cscript configure.js from the win32 directory to generate
the files needed to create the modbus DLL.

Thanks to Mirko Rajkovaca

Thanks Tobias Doerffel.

It will better to code something such as:
https://github.com/crossroads-io/libxs/blob/master/src/err.cpp

I don't intend to rewrite glib neither :(

Thanks Giampaolo Bellini.

- depends of automake 1.11
- C99
- pic-only
- more warning C flags
- remove obscure checks
- don't print directories
- add libmodbus.pc to clean files
- remove -Werror

Thanks to Damian Zieliński.

Add standalone Makefiles for the modbus DLL and tests, using the modbus DLL.