* Now that vsync off explicitly sets swap interval, it's clear that
we've been using driver defaults (vsync on) up until now.
* Try to enable normal vsync before late swap tearing. The latter
doesn't constrain framerate and looks basically identical to vsync
off.
- Set default GL clear color to black, rather than white
- Revert changes to ImageComponent intialization that cause white flashes
- Increased ALSA buffer to prevent buffer underruns which stall CPU momentarily
- Improved carousel texture buffering based on navigation direction and speed