This is a wrapper around Erik de Castro Lopo's libsamplerate (aka Secret
Rabbit Code) for high-quality sample rate conversion.

It implements all three APIs available in libsamplerate:
- Simple API: for resampling a large chunk of data with a single library
  call
- Full API: for obtaining the resampled signal from successive chunks of
  data
- Callback API: like Full API, but input samples are provided by a
  callback function
