First HW boot init cycle with clear register names defined
Add first boot debug flag
Remove all code for blocked sensor feature

In a future HW revision the block detection is built into the sensor
using IR. Though this current implementation works reasonably well, it
uses a visual LED pulse that can be distracting to the wearer in
certain occasions.
Improved first boot debug message
Refactored main RGBC sample loop
Refactored all I2C speed calls out to functions
Make sure averages are pre-filled at start of loop
Fix symbol reference for button input pin
Remove unused byte variable
Remove another unused variable
Rename i to index for clarity
Refactor variable usage to allow for transparent sensor
Refactor and rename led flashing routine
Add in response to user button press
Improve LED animation to allow for UI pulsing effects
Disable DEBUG_FIRST_BOOT (uncomment if needed)
Tidy up some comments
Changed multiline comment format
Removed a scratch variable ready for transparent sensor use.
Button press now outputs status before starting to blink