fixes #113

AudioControlWM8731::inputLevel(float n)

fixes #115

Add AK4558 CODEC support / Merge branch 'master' of https://github.com/MickMad/Audio

This reverts commit f0b376d3f6.

Adding useful functions to setup all the configurable options in the
CODEC (not yet finished)

https://forum.pjrc.com/threads/32252-Different-Range-FFT-Algorithm?p=91895&viewfull=1#post91895

More waveforms

One write was out-of-bounds due to worng address put (I was using the
device address rather than the register address), another write
overwrote the Power Management register with the Mode Control register.
Now everything works. Added two exampes: SineOutTest that puts two
sinewaves on the outputs, and PassthroughTest that connects the two
inputs to the two outputs.

This reverts commit 8d8350bf07.

The address was wrongly put to 0x10 + the two hardware set bits, while
it has to be 10 decimal, or 0x0A. Silly me.

The PIN_PDN was not set as output, therefore it would not transition to
LOW for 150 ns and then stay HIGH to properly enable the CODEC. The
CODEC now powers up, at least.

The test puts a 440 Hz sinewave on one channel, and a 220 Hz on the
other