New Hardware, some new features

I think we are just about to release here! I've added too many features to really remember, and I've also revised the hardware again. Here are some features that I did recently, so I can remember them:

• global volume control. This controls the gain on the headphone amp, so you can push it a bit louder when using big headphones.
• midi sync in / usb midi merge. The midi sync now follows song offset & song continue, in addition to the clock.
• sound usage / pattern usage. When selecting a pattern or a voice, you can see which patterns have notes on them & which voices in the current pattern have notes