midimaps

[felixroos]

after discussion in #1212 this PR adds support for defining midimaps:

// defines a midimap for the given name
midmaps({
  miniv3: { 
    lpf: { ccn: 74, min:0, max:20000, exp:0.5 },
    gain: { ccn: 7, min:0, max:1 }
  }
})
// create helper function to use the midimap and the default midi device
register('miniv3', pat => pat.midimap('miniv3').midi())

// because it's midi, we can send stuff in parallel
$: note("[<g bb <d4!3 eb4>> -]*8").miniv3()
$: gain("<.25 .5 1>*8").miniv3()
$: lpf(sine.range(20,8000).slow(1)).segment(64).miniv3()

todo:

• doc
• load from url
• test
• gather feedback

[Bubobubobubobubo]

It makes sense to also collect #1244 now, as it was attached to PR #1212. Other than that, very good design 😄.