to capture chars at UART at 250000 baud.

Also lined up the >> 1 and / 2 mentioned earlier in the unconstrained I term issue,

Also improve the documentation of this and related options, and set
EXTRUDE_MINTEMP to 170 everywhere.

Replace all fastDigitalRead/Write() with READ/WRITE()

Define SCK_PIN, MISO_PIN, MOSI_PIN in pins.h if not already defined in the pins_*.h files.

Remove these conditional pin definitions from the pin-files. They are now always defined.

Define separate sets of SPI-pins for AT90USB with and without Teensy support in fastio.h.
Likely this was the main reason for all that confusion about the AT90USB-SPI pins.