AudioBaseInfo, AudioInfo and improvements

[pschatzmann]

I decided to rename the AudioBaseInfo to simply AudioInfo which is more natural!

I also noticed that many sketches contain the sample rate, channels and bits per sample as global variables in the top and in the sketch create an AudioBaseInfo (or new AudioInfo) and assign these values.

So for this old way of doing things

uint16_t sample_rate=44100;
uint8_t channels = 2;    
uint8_t bits_per_sample = 16;                                  
AudioInfo info;
info.sample_rate = sample_rate
info.channels = channels
info.bits_per_sample = bits_per_sample

Now we can just create a global AudioInfo object and assign the values in the constructor

AudioInfo info(44100, 2, 16);

[aqildad-create]

very appreciated .