Support ADPCM wave files

[tjvr]

Python hates certain wave files.

Error: unknown format: 17

For example this one.

[tjvr]

Apparently Scratch 2 uses "PCM or ADPCM wav, or Squeak's encoding in old projects"

[as-com]

To be more specific, it's IMA ADPCM mono 22050 Hz. However, I have gotten Scratch to play 44100 Hz files.

[tjvr]

@trumank wrote a patch for phosphorus for this, should anyone wish to port it https://github.com/nathan/phosphorus/pull/583

FWIW, this is the number-one feature request I get over email!

[FlashlightET]

nathan decided to delete his account so now that pull is unavailable

however there is an archive of phosphorus it should be in there somewhere