Feature Request: Custom buttons in raster format

[futuremotiondev]

It's really difficult to get SVG icons that look crisp at 16x16px. Especially icons that contain text.

For instance I'm trying to create a button representing Adobe Illustrator, and this is how it's rendering:

If we could use PNG and specify @1x / @2x / etc. That would really improve the appearance of the buttons, and the plugin as a result would look more professional.

Any chance of being able to use PNG?