Modbus_RTU_lib - scalable, platform independent Modbus RTU library.

What's done:

	Slave mode:
	- read/write holding registers
	- read input registers

	Master mode:
	- none

TODO:

	Slave mode:
	- read/set coils (?)
	
	Master mode:
	- all

AVR_test - simple library test with AVR ATmega8. ex_use.c is a Q&D Modbus RTU slave, with 16 holding, 16 input registers and baudrate set to 600.

Notes:

	CRC checking disabled for testing purposes.