[Tones] added a new library for generating tones, notes, and melodies

- Tones library allows to generate tones, notes and melodies, on a given
output pin
Library is supposed to be compiled and linked as a static library
- Note class allows to handle notes
- AudioToneGenerator class allows to generates audio signals
- NoteGenerator class allows to generates notes
- MelodyGenerator class allows to generates melodies
Merge branch 'master' of https://github.com/sebastienjean/arduino-yasolibs.git