Replace |& with 2>&1 | and drop brew install bash on macOS
Add DISPLAY_PIXEL_BYTES, DISPLAY_ATTR_BYTES, and DISPLAY_FILE_SIZE constants
Simplify display_all_dirty initialisation to a bitmask expression
Fix use-after-free in SDL audio device setup
Fix a couple of sign compare warnings
Enable -Wextra and -Wsign-compare in default GCC warning flags
Add unit tests for libspectrum_machine_name() and libspectrum_joystick_name()
Blend PAL composite scaler chroma across lines