Public issue https://github.com/dr-soft/miniaudio/issues/128

This commit also renames ma_resampler_process() to
ma_resampler_process_pcm_frames().

  * ma_resampler_get_required_input_frame_count()
  * ma_resampler_get_expected_output_frame_count()

These have not yet been implemented for the Speex backend.

This commit also adds an APIs for setting changing the rate:

  * ma_resampler_set_rate()
  * ma_resampler_set_rate_ratio()

Automatic stream routing should only be used when the ma_device object
is initialized with a device ID of NULL. When it's non-NULL (i.e. an
explicit device) it should not perform automatic stream routing. It
looks like the WASAPI backend is not respecting this requirements and
is enabling automatic stream routing in all cases.

Public issue #127

The rationale for this is to test that the MA_NO_DECODING option is
compiling clean.

Emscripten no longer supports the -std=c* and -ansi compiler flags.

Fixed iOS crash in route change handler under ARC

Fixed some more integer cast warnings on iOS

Public issue #106