Significant improvements made as OOSMOS was used to develop multiple FDA approved medical devices.

Added user contributed ADC button.

Merged pull request to fix adc issue on ATmega32u4.

Fix regression in sw.c.

Implement nearly all CLang-tidy suggestions.

Refactor to use unsigned instead of int where appropriate.

StateThread.c now shows an example of using Thread-Specific Storage (TSS)

Refactor select Thread functions to reduce footprint.

Add oosmos_ThreadDelayUS & oosmos_ThreadDelaySeconds.

Update copyright year.