Added TWI baud rate prescaler and bit length parameters to the TWI_Init() function (thanks to Thomas Herlinghaus).

Make sure the peripheral driver .c files include the driver dispatch header, rather than the architecture specific header files.

Rename architecture specific driver files, to make them appear with uniquely identifying filenames in the documentation.

Add new ARCH option to the makefiles to (eventually) specify the target device architecture. Update non-usb peripheral drivers to reflect future multiple architecture support.

Update Temperature board driver to be AVR32 compatible when the ADC peripheral driver is eventually ported. Make architecture includes explicit for both the AVR32 and the AVR8, to make way for future architecture ports.

Add SPI driver aliases for the old function names in the AVR8 driver, so that existing code will still compile against the new version.

Fixed software PDI/TPI programming mode in the AVRISP project not correctly toggling just the clock pin.

Fix broken AVR8 Serial peripheral driver.