Added Note class

Represents a note. Handles the conversion between MIDI note number,
name, and frequency.
Working on the Staff/Note model
Implemented note to staff Y position function
Split classes in different files
Minor change
Added ledger lines representation
Added skeleton classes for NoteProviders
First version of NoteProviderKeyboard

Hacked to make it up update the presenter
Working on showing sharp/flat notes
Added note name next to staff representation
Fixed Y Pos calculation for flat notes
Added listener to Staff to which Presenter registers
Adding Exercise infrastructure
Exercise now working
Improved log
Minor improvements
Updated note provider more often
Create README.md

Adding the solution generation command as I never remember
Update README.md