wrote quick project-framework code b/c tired of doing it
also starting up skeleton on ADC/temp-sensor code
ADC demo.  Switching light as distance sensor.

Need to un-fancify this for a smiple sensor example.
got built-in temp working with Mega48P.  Only works with P series.  Boo...
working demo of distance sensor, toggling on/off in series
working demo of distance sensor, toggling on/off in series
unfiltered, raw values
oversampling + MA FTW
comments, slight tweak.  voltmeter working well.
Merging in from github.  Possibly will undo.  Why did my home version not track these?

Merge branch 'master' of github.com:hexagon5un/learningAVR

* 'master' of github.com:hexagon5un/learningAVR:
  changes made during final edit of timer, interrupt, and pwm chapters