Renamed the init functions to be more standard.
Got loopback, interrupt-based SPI code working.
Switched to polling approach for SPI data.
Switched to sending and receiving a byte at a time.
Changed to simple echo slave mode.
Fixed the CPOL and CPHA.
Got the communication of commands working fully.
Factored out a function to read from SPI.
Merge branch 'features/spi-communication' into development