uart_protocol.c: Remove todo items already worked off or not longer of concern
Update and/or remove references to pwm_set_color_step()
pwm.c: pwm_set_brightness(): Change way values within pwm_table are addressed

This makes more clear that an element of pwm_table is addressed.
pwm: Refine Doxygen comment of various entities
pwm: Remove pwm_on_off()
pwm: Rename pwm_set_base_brightness_step() to pwm_set_base_brightness()
pwm.c: Add comments describing the setup of the involved timers

These comments are excerpts from the datasheet and should make the
meaning of the various assignments more clear.
pwm: pwm_get_color(): Return pointer to pwm_color directly.
pwm.c: Mark outputVals() and outputPointer() as static
pwm: Rename remaining pwm_step_*() functions
pwm.c: modifyLdrBrightness2pwmStep(): Move variables down where they are used
pwm.c: interpolate(): Fix coding style guideline violation
pwm.c: Rename pwm_set_brightness() to pwm_accommodate_brightness()