This resolves an irritating issue in the code editor where SDL2-specific functions could't be found. Not entirely sure about the SDL include file logic for other operating systems than Linux so the #ifdef directives may need to be updated further at a later date.
Ensure that deinit() removes the current sInstance so that the next call
to AudioManager::getInstance() will re-initialize audio correctly.
Remove explicit calls to AudioManager::init() and instead rely on
Sound::play() to initialize audio when needed.
- 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
