[Fix] With new installations (and probably also upgraded ones), it was possible that OpenMPT was internally rendering at a different sample rate than the sound device was outputting (https://forum.openmpt.org/index.php?topic=5265.0).
The current fix changes the default mix rate for sound device structs to 44KHz (was 48Khz) to be compatible with the default mix rate in the mixer. The problem is that somehow the 48KHz were not propagated to the mixer, so of course this is only a quick'n'easy fix for the new OpenMPT and still needs to be fixed properly.

[Doc] Updated release note documents.
[Mod] OpenMPT: Version is now 1.23.02.00

git-svn-id: https://source.openmpt.org/svn/openmpt/trunk/OpenMPT@4035 56274372-70c3-4bfc-bfc3-4c3a0b034d27