Added new DATAFLASH_CHIP_MASK() macro to the Dataflash driver, which returns the Dataflash select mask for the given chip index.
Updated MassStorage device block write routines to use ping-pong Dataflash buffering to increase throughput by around 30%.
Added parameter directions to function parameter documentation.
Added new experimental FAST_STREAM_FUNCTIONS compile time option to speed up stream transfers at the expense of a higher FLASH consumption (needs testing to verify improved throughput).