TeoriaNote#scientific() allowing to exclude octave number from note name

Modified version of the *teoria.note.scientific()* method. 
When used like this: teoria.note.scientific(true),
it excludes the octave number from the note name output string.

Using this modified version of the method will greatly simplify use cases in which you need the note name (formatted with scientific pitch notation) as an upper case letter with the corresponding accidental only. Before, this could only be achieved with an hack making note.name upper case and then concatenating note.name and note.accidental together.

It follows the pattern of the note.toString([dontShow]) method and should therefore be convenient to use.

- updated and added relevant documentation