Consider removing `LV2` from the UI design

[dromer]

Now that it's no longer an LV2-only plugin, the UI can probably use an update :)

[AnClark]

Which UI should I remove? The UI code in src/?

I don't use any UI-related code in src/. I only include the directory for the synth engine only.

[dromer]

I meant:

So that would be src/gfx/back.png ?

[AnClark]

I see, but this may needs a bunch of work.

The original author does not provide the XCF source file of background image. I may need to edit the image with GIMP or Photoshop, and erase the "LV2" logo.

To make it prettier, I may need to re-design the logo as well. However I'm not good at UI design.