updated I2C driver to allow using I2C2 or I2C1 at compile time - call i2cInit with I2CDEV_1 or _2.
Applied same to SOFT_I2C driver (but the pin config is compile-time #define)

Conflicts:

	src/board.h
	src/drv_i2c.h
	src/drv_system.c
	src/main/drivers/bus_i2c_soft.c
	src/main/drivers/bus_i2c_stm32f10x.c