trivial: Fix SPI comment
Use a 24MHz clock like ColorHug+
trivial: Only support the 18F46J50
trivial: Add the max calibration index as a constant
trivial: Update the shared header file with details about ColorHug+
trivial: Whitespace changes
trivial: Remove some 'goto out's
trivial: Add error codes to the shared header from ColorHug+
Add error codes for the different i2c failures
trivial: Use sensible values for the sensor self test
Allow prototyping on boards without the SRAM or temp sensor
Make the MCD04 code actually work against real life hardware