Live retuning, recording file names, bug fixes

• New: Add live-retuning capabilities
  • In the past, microwave always used Single Note Tuning Change messages to retune external synthesizers
  • With the newest version the tuning method (--tun-method) can be full, octave, channel or pitch-bend
• Improvement: You can now specify the file prefix for wav recordings using the --wav-prefix parameter
• Bug fix: The scale degree offset was rendered with the wrong signum (+ instead of - and vice versa)
• Bug fix: The default-envelope indicator wasn't rendered correctly