gdi32: Extract the constituent TrueType files from Mac suitcase fonts into the user's caches directory
and use these instead of the original suitcase.

Keep increasing the buffer until the returned length is more than two
records smaller than the buffer we provided.

Rather than have the Audio Unit render callback traverse the queue of wave
headers looking for complete ones, and sending a message to the message thread
for each one it finds, just send one message to tell the message thread to do
that work itself.  The render callback is called in a real-time priority
thread and is expected to return as quickly as possible.

wodHelper_PlayPtrNext is only called when state == WINE_WS_PLAYING.  Also, it
clears dwPartialOffset itself.

wodWrite only calls wodHelper_BeginWaveHdr[Write] with a non-NULL lpWaveHdr
parameter.  wodWrite is not called from the Audio Unit render callback, so it
can use Wine debug channels.

This refactoring prepares the ground for subsequent refactoring of
wodHelper_BeginWaveHdr.

into a DECIMAL instead of a double as an intermediate step.