Use analogPinToChannel if it's defined
Removed call to analogPinToChannel for Leonardo
Check if ATmega32u4 is defined

Needed in order to work with Arduino Leonardo
Removed double instance of the same code
Update incorrect docs in tonePitchFollower example

The comments state that the speaker should be on pin 8, but the code references pin 9. Updated the comments to reflect the correct pin.
Merge pull request #1465 from mcoms/patch-1

Update incorrect docs in tonePitchFollower example
Merge branch 'issue1366' of github.com:Lauszus/Arduino into Lauszus-issue1366