DRIVERS: AD7780: AD7780_ConvertToVoltage() returns now milivolts.
PMODS: Addded the PmodAD3, PmodAD4 and PmodAD5 demos for PIC32.
DRIVERS: AD7193: AD7193_ConvertToVolts() returns now milivolts.
DRIVERS: AD7980: AD7980_Init() has to return -1 (char) as error.