Merge topic branch t/wmadec into master

Merge topic branch t/wmadec into master

A few patches which remove unused code from the wma decoder and audio
format handler. Notably, noise coding was removed completely since
it was only used for unusual bit rates. Most likely, it never worked
in the first place.

* refs/heads/t/wmadec:
  wmadec: Fix typo in comment.
  wmadec: Remove a stale comment in wma_init().
  wmadec: Kill pointless start/end computations.
  wmadec: Remove noise coding.
  wmadec: Simplify wma_init().
  wmadec: Remove fft().