Public issue https://github.com/mackron/miniaudio/issues/341

This was happening because ma_log_level_to_string() was only being
included when MA_DEBUG_OUTPUT is enabled.

Fix `ma_log_postv` not returning anything under certain circumstances

The `__STDC_VERSION__ >= 199901L` and the `_MSC_VER >= 1200` code
had different styles for handling errors, so I've made them match.

MSVC 6 was printing a warning about this.

This is configurable on a per-device basis. Denormals will be disabled
by default.

This makes devices and decoders more robust when the resampler does not
support retrieval of required input frame counts from a given output
frame count, which can happen with custom resamplers.

This changes ma_resampler_get_required_input_frame_count() and
ma_resampler_get_expected_output_frame_count() to return a result code
so that MA_NOT_IMPLEMENTED can be checked and an alternative code path
can be run for dealing with caching of data.

This removes the dependency on the ma_resampler object.

Public issue https://github.com/mackron/miniaudio/issues/162