This change makes a device run it's own loop with a timer to better
simulate an actual device.

Automatic device switching has not yet been tested with this.

This work is isolated to WASAPI for now while I figure out requirements
and the API.

This will be the basis for an improved main loop in the audio thread.

# Conflicts:
#	mini_al.h

This change makes it consistent with mal_pcm_converter, mal_src, etc.

All functions have been renamed from mal_dsp_*() to
mal_pcm_converter_*(). All structures have been renamed from mal_dsp*
to mal_pcm_converter*.

* Return MAL_SHARE_MODE_NOT_SUPPORTED if SetCooperativeLevel fails.
* Always fail with MAL_SHARE_MODE_NOT_SUPPORTED if exclusive mode is
  requested for capture.