[web-midi-api] Inputs and outputs now Maplike, among others - fixes issue #81, issue #59, issue #2. (#82)

Seeing approval from my co-editor, I'm going to go ahead and suggest this be pulled in to the main editor's draft.
You can merge this Pull Request by running:

  git pull https://github.com/cwilso/web-midi-api gh-pages

Or you can view, comment on it, or merge it online at:

  https://github.com/WebAudio/web-midi-api/pull/82

-- Commit Summary --

  * Step 1 of fixing issue #2
  * Adding MIDIInputMap interface; work in progress
  * Fixes issue #81, issue #59, and issue #2.  Also incorporates fixes to issue #77 and issue #78.
  * Minor typo - changing unintended markup to </>
  * Merge pull request #1 from cwilso/cwilso-edit
  * minor ReSpec front matter fixes - draft URL, github links, shortname
  * Merge pull request #2 from olivierthereaux/gh-pages

-- File Changes --

    M index.html (443)

-- Patch Links --

https://github.com/WebAudio/web-midi-api/pull/82.patch
https://github.com/WebAudio/web-midi-api/pull/82.diff