* Renamed all classes that shared a name with their parent instance.
* Moved core files to more appropriate locations.
* Renamed PlipChip8 to Chip8Instance
* Plip natively uses 32-bit stereo floats. The frontend is responsible for
converting this to the system's native format.
* Somewhat buggy (wrt conversion) SDL audio implementation added.
* Test code included, free of charge!
* Implemented a format-agnostic way of plotting pixels and getting the
number of bytes per pixel.
* PlipInput can no longer be inherited.
* Added width/height getters to the video subsystem.
* Properly initialized SDL2 and added a temporary event loop (required to
get the window to appear on macOS).
* Sorted all source files into appropriately named directories.
* Removed version header generation for the GUI application.
* Added a static library function to retrieve the version number.
* Fixed bug that caused the version flag to fail unless the core/filename
were specified.
* Renamed version.h to PlipVersion.h.
Ian Burgmyer