vht 0.3 - the probability edition

Besides fixing a ton of bugs, and inadvertently introducing new ones, this version focused on probability. What's new:

• randomised velocities and timeshifts (mid click and drag)
• probabilities column (ctrl+f5) for notes
• mandy - a fractal track strummer
• new render mode - what u'd hear for exporting those never-ending mandie's
• more keyboard shortcuts
• highest version number ever