ProTracker 2 clone v1.11

• The BLEP synthesis has been improved for slightly less resampling aliasing.
  aciddose (the writer of the BLEP implementation) is currently working on it
  to see if it can be further improved, but as for now this should in theory be
  a little bit better than the old one.
• Bugfix: Reset play mode to "Play song" when double-clicking files associated
  with the PT2 clone.
• Bugfix: The MOD2WAV buffer was too small and could cause nasty issues when
  rendering a song with low BPM values.
• MOD2WAV now renders the song at 96kHz, so that the user has more resolution
  before converting the WAV to the format/frequency of choice.
• Don't include high-pass filter and dithering in PAT2SMP
• Code cleanup