fix bug where winamp plugin configuration was not being saved because the folder (the same one that the dll was stored in) was not writable on newer Windows versions (now we use the application-specific data folder instead) - change the default configuration to include using WVC (correction) files and allowing multichannel playback - bump the revision from 2.8a to 2.8rc
add NSIS script for generating Winamp installer (currently works with NSIS 2.46)