0.9.6

• Massively update/cleanup XML comments and docs
• Include XML documentation in nuget package
• Various refactorings
• Minor enhancements / bugfixes:
  • Correct naming of methods NormalizePeak() / ChangePeak()
  • Add signal.Crossfade(), signal.FadeIn/Out() methods
  • Better implementation of DesignFilter.Fir() method
  • Better implementation of OnlineFeatureExtractor.VectorCount() method
  • Add implementation of FastDct3.DirectNorm() / FastDct2.InverseNorm()