Scales and Keys

[duncanmalashock]

• Scales are implemented with stacked intervals from step-to-step
• Scales no longer have Diatonic/Non-Diatonic difference
• Keys are major or minor, limited by the constructors they expose

The only "problem" is that diminished whole-half and diminished half-whole are not spelled according to the Wikipedia references we've checked. Run the tests and you'll see that C diminished half-whole is spelled:

C Db Eb Fb Gb Abb Bbb Cbb

But another way to look at it is that this is really the "correct" spelling when major and minor seconds are applied in sequence, and an enharmonic spelling function like the one we've discussed would take care of spelling these pitches in a way that a professional musician might prefer.

[duncanmalashock]

@battermann I like your changes! Nice work on importing scales automatically. I made very few changes except to fix some scale names (e.g. "alteredBb7" -> "alteredDoubleFlat7"), removing duplicates ("doubleHarmonic" == "byzantine", "majorPentatonic" == "mongolian", etc.), and categorizing by scale modes with comments in the file. I also standardized a few scale name conventions (e.g. flat 9 intead of flat 2, flat 13 instead of flat 6). My reference for these changes was Modern Jazz Voicings from Berklee Press.

It's ready to merge. Can you give this a quick re-review?