Make a plugin for AIMP player

I have some friends are like to use AIMP player. I would like to make a codec plugin of libADLMIDI and libOPNMIDI for that. Here is an SDK: https://www.aimp.ru/?do=download&os=windows&cat=sdk

The plugin will be placed into `utils/aimp-codec` directory and will work on Windows only (as player itself is Windows-only)
