Simplified module for Music and AudioStream
Added support for raw audio streaming (with example)

Still some work left...

...at least, directly, available if using directly audio module...

Moved AudioError enum inside audio.c

The only thing I did not change was the _g for globals. Is there any
other way we can mark globals?

Now floating point is either on or off. This simplifies the use of 16bit
vs float.

updateAudioContext is almost done

Ease of use considered in api and channels are more convenient as
unsigned char type.

Hiding the struct from user should protect from accidentally modifying
the mix channel. This could cause serious errors down the road.

Look over changes and give feedback please.

Now audio module can be used as standalone module