Feature: Add ability to write Float32 data to WAV, not just Int16

[chipaudette]

It would be great if we could write float32 data to the WAV files, not just Int16 data. Priority is on SD Writing, but eventually we should enable SD reading, too.

[chipaudette]

For writing, this is now implemented in a branch: https://github.com/Tympan/Tympan_Library/tree/feature/32bit_quad_i2s

Tested on RevE and RevD. Tested 2- and 4- channels. Tested at 44kHz and 96 kHz. Tested in Int16 and Float32. In my tests, howeve,r my maximum recording time was only a few minutes.

No effort has been put into the making the SD Reader compatible with Float32 WAVs.

[chipaudette]

Tag @cab-creare-com , @eyuan-creare

[chipaudette]

Just as a reminder, the capability to write Float32 to a WAV file is sitting in the 32-bit I2S branch of code. For anyone who wants to track the progress of that branch, its status is being reviewed and discussed over on issue #87.