TWI Slave

The origin code (protocols/ecmd/via_i2c) make use of an parse variable. It could happen that the twi master send his twi + W faster then the avr parses his data. This came because in the origin code the avr sends an ACK directly after receiving the last +R byte (0xA0).
i changed the code to disable the interrupt after receiving 0xA0, parse the data, and then send the last ACK for +R.